Time-Domain Terahertz - Toptica

Terahertz WavesThe Final Frontier of theElectromagnetic SpectrumBetween radio waves & infraredThe terahertz range refers to electromagnetic waves with frequencies between 100 GHz and 10 THz, or wavelengths between 3 mmand 30 μm. Light between radio waves and infrared has some unique properties. Terahertz waves can “look inside” plastics and textiles,paper and cardboard. Many biomolecules, proteins, explosives and narcotics also feature characteristic absorption lines – so-calledspectral “fingerprints” – at terahertz frequencies. Unlike X-rays, terahertz waves do not have any ionizing effect and are generallyconsidered biologically innocuous.Closing the terahertz gapFor a long time, it has been difficult to generate intensive, directional terahertz radiation, and the terahertz range was considered thefinal frontier of the electromagnetic spectrum. Now, frequencies between 0.5 and 10 THz have become the domain of laser-basedtechniques. Optoelectronic approaches use either femtosecond lasers or tunable diode lasers. Photomixers, photoconductive switchesor nonlinear crystals convert the near-infrared laser light into terahertz waves, either broadband or spectrally resolved. The terahertz gapis bridged at last.The complete portfolioTOPTICA has been cooperating with researchers in the terahertz arena from day one. As a result, TOPTICA is now the only company inthe world that serves scientists and engineers working with the two most important optoelectronic approaches – pulsed and continuouswave(cw) terahertz generation. Our FemtoFiber TM lasers form the basis of the TeraFlash TM system, a complete time-domain spectroscopyplatform. On the other hand, our tunable DFB diode lasers are the perfect match for GaAs or InGaAs photomixers, as used in ourTeraScan TM frequency-domain systems.

(c) SynView GmbHTerahertz ApplicationsWavenumber (1/cm)04.010 20 30 40 50 602.03.51.53.02.51.0ε 1ε 22.00.51.51.00.0 0.3 0.6 0.9 1.2 1.50.01.8Frequency (THz)SpectroscopyVarious applications of terahertz spectroscopy exist, as many gas molecules and organicsolids, including chemical agents and explosives, exhibit “fingerprints” at terahertzfrequencies. A spectrum can be acquired using either pulsed or cw terahertz radiation,and yields information on the complex refractive index of the sample. A time-domain(pulsed) measurement demonstrates an absorption signature with a decrease of theamplitude and a delay of the terahertz pulse. In a frequency-domain (cw) experiment, thesignature presents an attenuated signal and a phase shift of the terahertz wave.Since terahertz rays penetrate opaque materials such as paper, and are hardlyattenuated by aerosols, spectroscopy can aid in observing “inaccessible” settings (e.g.,through sealed envelopes or black smoke).Real part ε 1(black, left axis) andimaginary part ε 2(blue, right axis) ofthe dielectric constant of α-lactosemonohydrate, measured with cw-THzspectroscopy.(M. Grüninger, University of Cologne,Germany)4 | www.toptica.com

Ceramic knife hidden behind blackdenim.(TeraView Ltd.)Homeland securitySecurity-related applications benefit from both the chemical sensitivity and the imagingpotential of terahertz radiation. Terahertz-sensing can detect trace amounts of illicit drugswithin paper envelopes or can determine the compounds of a gas mixture. A powerfulapplication implemented with this method involves monitoring air quality in publicbuildings, where potentially threatening chemicals must be identified in a “cluttered”background of cleaning agents, perfumes, glues and paint. Terahertz imaging alsoallows the visualization of concealed weapons in parcels or shoes. The image contrastoriginates from the different refractive indices of the object and its surroundings.Terahertz imaging even reveals non-metallic objects, which present a challenge fortraditional detection techniques.y (mm)x (mm)Terahertz imaging of a plant leaf.Darker areas indicate a higher watercontent.(m. Koch, university of marburg, Germany)Humidity and hydration monitoringWater vapor strongly attenuates terahertz waves, and liquid water has an even strongereffect. On the other hand, water also provides a stark contrast in reflection-modeterahertz imaging. Measuring a sample’s transmission or reflection properties yieldsquantitative information on its water content. A new application emerging in the fieldof industrial process control assesses paper humidity in paper production lines. here,terahertz-based measurements provide the long-sought-after alternative to radioactiveemitters used to date.The high sensitivity of “water-contrast” terahertz imaging also allows in-situ measurementsof the water content of plant leaves. This helps to avoid drought stress and to optimizeirrigation strategies (e.g., for agricultural crops grown in arid regions).Terahertz image of Kevlar body armor,with a bullet hole.(SynView Gmbh)Non-destructive testingmany plastic compounds and synthetics appear transparent in terahertz light, a propertysuccessfully used for non-contact analysis and imaging of hidden objects. Via timeof-flighttechniques, pulsed terahertz radiation provides information on an object’sthickness, its absorption coefficient and refractive index, even in multi-layered samples.Scanning the sample with the help of a terahertz beam pinpoints sub-surface cracks,voids and delaminations.The availability of non-destructive testing routines will benefit a wide range of applications.For example, terahertz imaging of a polymeric airbag cover facilitates the extraction ofthe break line thickness with sub-millimeter resolution. In windmill blades, aircraft wingsor bullet-proof body armor, likewise, hidden defects can be localized.

Time-Domain Terahertz GenerationDirect and indirect sourcesThe spectroscopically relevant frequenciesfrom 0.5 – 5 THz prove difficult to access.electronic sources, such as voltagecontrolledoscillators with frequencymultipliers, offer power levels in the mWrange. However, they become inefficientat terahertz frequencies and provide ratherlimited frequency tuning. direct opticalsources, like quantum cascade lasers,must operate at cryogenic temperaturesand suffer from poor beam profiles andlow spectral purity.optoelectronic terahertz generation, anexpression for indirect methods, involvesnear-infrared laser light generating freecharge carriers in a semiconductor ororganic crystal. The charge carriers areaccelerated by internal or external electricfields and the resulting photocurrentbecomes the source of the terahertzwave.The ultrafast approachPulsed terahertz radiation is generatedwith femtosecond lasers. In a typical timedomainsetup, the laser pulse is split intwo, with one part traveling to the terahertzemitter, and the second part travelingto the detector, after interacting with asample.The ultrashort laser pulses produce acurrent transient in the emitter and as aresult, electromagnetic wave packets witha broad spectrum in the terahertz range.The detector works in a “pump and probe”fashion: the incident terahertz pulsechanges the properties of the material(e.g., conductivity or birefringence) andthe laser pulse probes this very effect. Avariable delay stage scans the terahertzwave packet with the much shorter“probe” pulse. A fast Fourier transform ofthe terahertz amplitude then produces theterahertz spectrum.AC BiasTerahertz pulse~Electric field amplitude (a.u.)105010 20 30Time (ps)fs laserTranslation StageTXRXLock-inDetectionSample position0.1Spectrum (Fourier transform)Photoconductive switch0.0110 nm @100 fsAmplitude (a.u.)1E-31E-4800 nm1E-50 1 2 3 4 5Frequency (THz)

Frequency-Domain Terahertz GenerationGive me a beat!Coherent signal detectioncontinuous-wave (cw) terahertz radiationis obtained by optical heterodyning inhigh-bandwidth photoconductors: theoutput of two cw lasers converts intoterahertz radiation, exactly at the differencefrequency of the lasers.The core component is the “photomixer,”a microscopic metal-semiconductor-metalstructure. near-infrared laser light irradiatesthis structure at two adjacent frequencies.Applying a bias voltage to the metalelectrodes then generates a photocurrentthat oscillates at the beat frequency.An antenna structure surrounding thephotomixer translates the oscillatingphotocurrent into the terahertz wave.State-of-the-art photomixers are based oneither GaAs or InGaAs/InP and require laserwavelengths below the semiconductorbandgap (i.e., around 850 nm or 1.5 μm,respectively).In a coherent detection scheme, a secondphotomixer serves as terahertz receiver.Similar to the pulsed scenario, both theterahertz wave and the original laserbeat illuminate the receiver. The incomingterahertz wave generates a voltage in theantenna while the laser beat modulatesthe conductivity of the photomixer. Theresulting photocurrent, typically in thenanoampère range, is proportional tothe amplitude of the incident terahertzelectric field. It further depends on thephase difference between the terahertzwave and the optical beat. Spectroscopicmeasurements commonly take advantageof both amplitude and phase data.coherent detection methods offer theadvantage of a very high efficiency, andcan attain a dynamic range in excess of80 dB and a noise-equivalent power of 10 pW/hz 1/2 .λ 1Laser #1AC bias~TXTHz waveSample positionLaser #2Laser beatRXλ 2Lock-indetection80Spectrum (Frequency scan)Dynamic range (dB)60402000.0 0.5 1.0 1.5 2.0Frequency (THz)

Time-Domain Terahertzultrafast Lasers and a Versatile Spectroscopy SystemPhotoconductive switches (GaAs or InGaAs/InP) and organic crystals(dAST, dSTmS, oh1) represent the most common pulsed terahertzemitters. Their excitation wavelengths range from 750 nm to 1.6 μm,wavelengths easily accessible with erbium-doped femtosecondfiber lasers and optional second harmonic generation. TOPTICA’sFemtoFiber pro Tm / FemtoFiber smart Tm lasers provide superiorspecifications that fit all common emitter types.owing to the use of robust saturable absorber mirror (SAm) technologyfor mode-locking, the lasers offer turnkey operation without anymechanical alignment.The versatile TeraFlash Tm platform combines FemtoFiber smart Tm lasertechnology with state-of-the-art InGaAs antennas. The all-fiber systemattains a bandwidth above 4 Thz and an outstanding dynamic range.FemtoFiber pro IR• Wavelength 1560 nm• Power > 350 mW• Pulse width < 100 fsFemtoFiber pro NIR• Wavelength 780 nm• Power > 140 mW• Pulse width < 100 fsFemtoFiber pro IRS• Wavelength 1570 nm• Power > 180 mW• Pulse width < 40 fs

Pick one: cw or Pulsed Terahertz?Highest bandwidth with time-domain systemsTime-domain and frequency-domain techniques each have merit. Time-domain terahertz spectroscopy offers the advantage of avery broad bandwidth: spectra acquired with photoconductive switches extend to 4 Thz, and crystal emitters even achieve 10 Thz.measurement speed provides the second advantage. The acquisition of a spectrum typically takes 0.1 .. 10 seconds, depending onthe number of traces averaged. Time-domain systems also lend themselves to the investigation of multi-layered samples, where depthinformation is retrieved via time-of-flight measurements.Best resolution with frequency-domain systemsFrequency-domain spectroscopy is the preferred choice for applications requiring highest spectral resolution. While a pulsedspectrometer usually offers a resolution on the 10 Ghz level, cw systems allow frequency control with single-megahertz precision.cw systems also provide the highest dynamic ranges, with peak values greater than 80 dB. Last but not least, frequency-domainspectroscopy enables spectrally-selective measurements. It is thus possible to zoom in on one spectral signature (e.g., to measurethe strength of a single absorption line).Dynamic range of a frequency-domainsystem (left) and a time-domainsystem (right). The dips are absorptionlines of water vapor. The circleshighlight the same set of lines.Specifications cw terahertz systems Pulsed terahertz systemsBandwidth 0.05 – 2 Thz, limited by lasers 0.1 – 4 .. 10 Thz, depending on emitterPeak dynamic range ~ 85 dB ~ 75 dBFrequency resolution 10 mhz Typ. 10 GhzSpectral sensitivity yes noAcquisition time(complete spectrum)minutes to hours, depending on resolutionand lock-in timemilliseconds to seconds, depending onnumber of averagesFemtoFErb 1560• Wavelength 1560 nm• Power > 100 mW• Pulse width < 100 fsInGaAs antennas• Bandwidth > 4 THz• 1 µW average power• SM/PM fiber pigtailTeraFlash• Bandwidth > 4 THz• Peak dynamic range > 70 dB• Resolution 4 .. 40 GHz, selectable

FemtoFiber pro IR / IRShigh-Power Infrared Femtosecond Fiber LasersThe FemtoFiber pro Ir is the base unit of ToPTIcA’s FemtoFiber pro series. Itcomprises a robust, SAM mode-locked oscillator and a power amplifier, andprovides an industry-record average power of > 350 mW. The pulse duration isbelow 100 fs.The short-pulse version FemtoFiber pro IRS features an additional non-linear fiberto generate pulses of less than 40 fs. The pulse width can be controlled by anautomated feedback loop.Both lasers are realized in an alignment-free, polarization-maintaining all-fiber setup,and require neither water nor air cooling. Pulse durations and power levels are wellsuitedfor terahertz generation in organic crystals or InGaAs antennas.Key features· erbium fiber lasers with SAm modelockedoscillator and amplifier· FemtoFiber pro IR:Pulse duration < 100 fs,average power > 350 mW· FemtoFiber pro IRS:Pulse duration < 40 fs,average power > 180 mWSpecifications FemtoFiber pro IR FemtoFiber pro IRSFundamental wavelength 1560 nm 1570 nmLaser output power > 350 mW > 180mWPulse width < 100 fs < 40 fsRepetition rate80 mhz(optional: 40 mhz)80 mhzBeam shape Tem 00M² < 1.2Applications· Terahertz generation in organiccrystals (dAST, dSTmS, oh1)· Terahertz generation in InGaAsphotoconductive switchesBeam divergence < 2 mrad < 1 mradLinear polarization > 95%, horizontal > 95%, verticalOutput couplingFree space88Autocorrelation intensity642Autocorrelation intensity6420-0.6 -0.4 -0.2 0.0 0.2 0.4 0.6Time delay (ps)0-0.8 -0.4 0.0 0.4 0.8Time delay (ps)Autocorrelation pulse width of FemtoFiber pro IR:< 100 fs at 1560 nm.Autocorrelation pulse width of FemtoFiber pro IRS:< 30 fs at 1560 nm.order informationFemtoFiber pro IRFemtoFiber pro IRSM40High-power ultrafast Erbium fiber laser, 1560 nmErbium fiber laser with pulse compression (< 40 fs)repetition rate 40 mhz @ identical average power (only for FemtoFiber pro Ir)

FemtoFiber pro NIRnear-Infrared Femtosecond Fiber LaserThe FemtoFiber pro NIR includes an Erbium fiber laser with a SAM mode-lockedoscillator, a power amplifier, and a second harmonic generation (SHG) stage. It offersboth the fundamental and the frequency-doubled output, and the user selects thewavelength with a manual switch. In a customized design, the laser emits both beamssimultaneously from separate output ports. A motorized prism compressor optimizesthe pulse characteristics at either wavelength, attaining pulse durations below 100 fs.The FemtoFiber pro nIr provides an ideal laser source for terahertz generation viaGaAs-based photoconductive switches or for hybrid systems with an organic emitter(dAST, dSTmS) and a GaAs detector.SpecificationsFemtoFiber pro NIRWavelength 1560 nm 780 nmLaser output power > 350 mW > 140 mWPulse width< 100 fsRepetition rate80 mhz (optional: 40 mhz)Key features· SAm mode-locked oscillator,amplifier and ShG stage· Pulse duration < 100 fs, averagepower > 140 mW @ 780 nm· Free-beam output, switchablebetween 780 nm and 1560 nmBeam shape Tem 00M² < 1.2Beam divergence < 2 mrad < 1 mradLinear polarization> 95%, horizontalOutput couplingFree spaceWavelength selectionmanual slide bar (optional: 2-color output)Applications· Terahertz generation in GaAsphotoconductive switches· hybrid systems (e.g., with dASTemitter and GaAs detector)0.1Autocorrelation intensityAmplitude (a.u.)0.011E-31E-4Time delay (ps)1E-50 1 2 3 4 5Frequency (THz)Autocorrelation pulse width of FemtoFiber pro NIR:< 100 fs at 780 nm.THz spectrum, acquired with the FemtoFiber proNIR and GaAs antennas. (otsuka electronics)order informationFemtoFiber pro NIRM40Two-color outputFrequency-doubled ultrafast Erbium fiber laser, 1560 nm and 780 nmrepetition rate 40 mhzSimultaneous availability of the fundamental and frequency-doubled wavelength (2 output ports)

FemtoFErb 1560compact ultrafast Laser with optional Fiber deliveryToPTIcA’ s FemtoFerb 1560, the most compact ultrafast laser on the market, comprisesa robust, SAM mode-locked fiber oscillator and a power amplifier. It generates pulseswith more than 100 mW average power and pulse durations well below 100 fs. Thesetup includes only polarization-maintaining fiber components.By default, the laser features a 20 cm fiber patchcord which delivers the short pulses.One or two SM/PM fiber extensions of 5 m length can be added on demand to replacecomplex beam delivery setups by flexible fiber solutions.The FemtoFerb provides an ideal match for InGaAs antennas and organic terahertzemitters alike, and also functions in ToPTIcA’s TeraFlash spectroscopy platform.Key features1.0· most compact ultrafast erbium fiberlaser· Pulse duration < 100 fs (typ. 70 fs),average power > 100 mW· optional: Sm/Pm fiber delivery, 5 mfiber lengthAutocorrelation intensity0.80.60.40.2autocorrelationsech-fitAmplitude (a.u.)10 0 Frequency (THz)10 -110 -210 -3Applications· Terahertz generation in InGaAsphotoconductive switches· Terahertz generation in organiccrystals (dAST, dSTmS, oh1)0.0-1.5 -1.0 -0.5 0.0 0.5 1.0 1.5Time delay (ps)Autocorrelation pulse width ofFemtoFErb 1560: typically 70 fs.10 -40 2 4 6 8 10 12 14Terahertz amplitude spectrum, acquiredwith the FemtoFErb 1560 and a DSTMScrystal. (rainbow Photonics)Specifications FemtoFErb 1560Fundamental wavelengthLaser output powerPulse widthSpectral widthTime-bandwidth productRepetition rateOutput couplingPower supply1560 nm> 100 mW, fixed power< 100 fs (70 fs typ.)40 nm typ.0.5 typ.100 mhzSM/PM fiber pigtail, 20 cm standard12 V dcFiber Delivery OptionLaser output powerFd5-Pm> 60 mW, or 2x > 30 mW*Pulse width < 120 fsFiber5 m SM/PM fiber with FC/APC connector or:2 x 5 m SM/PM fiber with FC/APC connectorsorder information12 | www.toptica.comFemtoFErb 1560FD5-PM*Compact femtosecond Erbium fiber laser, withfiber output (20 cm pigtail) & integrated electronicsFiber delivery, 5 m SM/PM fiber*For two fiber outputs, please order the FD5-PM option twice.

Photoconductive SwitchesFiber-coupled InGaAs AntennasPulsed terahertz generation made easy: fiber-pigtailed InGaAs antennas provide anideal match for our turnkey, telecom-band femtosecond lasers. The photoconductiveswitches, developed by the Fraunhofer heinrich-hertz Institute (hhI, Berlin/Germany),use a multi-stack design of InGaAs absorber layers and InAlAs trapping layers to reducethe dark conductivity of the semiconductor and maximize the efficiency of the device.The emitter and detector modules feature a strip-line and a dipole antenna, respectively,and are packaged with a Silicon lens and SM/PM fiber. Their bandwidth spans morethan 4 Thz. Together with the FemtoFerb 1560, these modules make up the corecomponents of the TeraFlash platform.InAlAs (8 nm)InGaAs:Be (12 nm)Key featuresElectric field amplitude (a.u)20100-10-20Semi-insulating InP substrate100periods· compact modules with Sm/Pm fiberpigtail and Silicon lens· high terahertz power: 1 μW average· Large bandwidth > 4 Thz0 10 20 30 40 50 60 70Time (ps)Pulse trace of an InGaAsphotoconductive switch.Multi-layer structure of the emitter/receiver modules.Applications· high-bandwidth spectroscopy (e.g.,explosives or liquid crystals)· Industrial process controlSpecificationsSemiconductor materialWavelengthEmitterReceiverEmitter / receiverbandwidthAverage terahertz power(typ.)PackageRecommended operatingconditions#EK-000781 / #EK-000782multi-layer structure of InGaAs and InAlAs on InP1560 nmPhotoconductive switchwith 25 μm strip-line antennaPhotoconductive switchwith 25 μm dipole antenna,10 μm gap> 4 Thz1 μW @ 20 mW laser powercylindrical, Ø 30 mm, integrated Si lens andSM/PM fiber pigtailLaser power 20 mW averagemax. bias ± 20 V (emitter),± 3 V (receiver, only for testing)order information#EK-000781#EK-000782InGaAs/InP Thz emitter: Photoconductive switchwith strip-line antenna and SM/PM fiber pigtailInGaAs/InP Thz receiver: Photoconductive switchwith dipole antenna and SM/PM fiber pigtailwww.toptica.com | 13note: The photoconductive switches are only available in combination with one of ToPTIcA’s femtosecondlasers (FemtoFerb 1560, FemtoFiber pro Ir or FemtoFiber pro IrS).

TeraFlash TMTime-Domain Terahertz Spectroscopy PlatformThe new TeraFlash system combines TOPTICA’s established FemtoFErb laser andstate-of-the-art InGaAs photoconductive switches into a table-top terahertz platform,based on mature 1.5 µm technology. Owing to a highly precise mechanical delay stage,the TeraFlash achieves a peak dynamic range of more than 70 dB. In “precise scan”mode, the system attains a bandwidth of 4 THz and a resolution better than 10 GHz.Alternatively, in “fast scan” mode, the system acquires a pulse trace in only 50 ms.Equipped with SM/PM fiber pigtails, the antenna modules can be flexibly arrangedaccording to the requirements of the experiment in question.Key features· Versatile time-domain terahertzplatform· Fiber-coupled InGaAsphotoconductive switches· High bandwidth > 4 THz,peak dynamic range > 70 dBVoice coil +position sensorfree space collimators fibersPath lengthcompensationto emitterbias voltageFemtoFErb 1560+ fiber deliveryto detectorSM/PMFC/APCSMBSM/PMFC/APCApplications· High-bandwidth spectroscopy(e.g., explosives or liquid crystals)· Industrial process controlReal-time data processing boardSMAdetector signalPCSchematic diagram of the TeraFlash platform. Blue lines depict electricsignals, red lines the optical signals.Amplitude (a.u)Electric field amplitude (a.u.)20Reference10α-Lactose0-10-20-30-400 20 40 60 80 100Time (ps)1E-101E-111E-120.0 0.5 1.0 1.5 2.0 2.5Frequency (THz)Pulse trace and absorption spectrumof α-lactose monohydrate (blue) andan air reference (black)Precise timekeepingA fast Fourier transform converts the time trace of the terahertz field amplitude into thecorresponding spectrum. The dynamic range of the spectrum (i.e., the ratio of the peaksignal to the noise level) depends on the timing accuracy with which the terahertz pulseis sampled, which in turn is determined by the length jitter of the delay stage used.To achieve a dynamic range above 70 dB, the delay length, given by the momentaryposition of the moveable retro-reflector, must be known with submicron accuracy. TheTeraFlash uses a voice-coil delay with a timing resolution of 1.2 fs, thus measuring thedelay length to better than 400 nm – the secret behind the superb dynamic range ofthe instrument.Flexible scan speedFourier theory determines not only the dynamic range, but also the frequency resolutionof a time-domain terahertz spectrum: the longer the delay stage scan (i.e., the samplingtime of the pulse), the better the resolution. The maximum scan range of the TeraFlashis 200 ps, which translates into a resolution better than 5 GHz. In addition, the user canchoose to average a number of traces in order to exploit the maximum dynamic range.If, however, the measurement speed matters most, then the scan time can be reducedto 25 ps, and 20 pulse traces per second can be acquired – still at a peak dynamicrange of 55 dB.The control software can flexibly adjust the scan time and the number of averages.Dipole antenna with mesa structure(Fraunhofer Heinrich-Hertz Institute,Berlin / Germany)14 | www.toptica.com

SpecificationsComponentsTeraFlashFemtoFErb 1560, 2x SM/PM fiber delivery,mechanical delay stage, 2 InGaAs photoconductive switches,complete electronics for data acquisitionLaser FemtoFerb 1560Laser wavelengthLaser outputpower (fiber output)Laser pulse width1560 nm2x 30 mW< 120 fsElectric field amplitude (a.u.)20100-10-20-30-40ReferencePolypropylene0 5 10 15 20 25 30Time (ps)Pulse shift introduced by a 2 mmpolypropylene slab.Laser repetition rate100 mhzFiber deliveryTerahertz emitterTerahertz receiverTerahertz spectral rangeAverage terahertzpower (typ.)Peak dynamic rangeIncluded: 2x FD5-PM, SM/PM fibers#eK-000781, InGaAs photoconductive switch with 25 μmstrip-line antenna, 1 m fiber pigtail#eK-000782, InGaAs photoconductive switch with 25 μmdipole antenna, 10 µm gap, 1 m fiber pigtail0.1 – 4 Thz1 μW> 70 dB (75 dB typ.)Electric field amplitude (a.u.)100-10-20-30Reference (air)LC fast axisLC slow axis-400 5 10 15 20 25Time (ps)Pulse traces of a birefringent liquidcrystal polymer (Ticona A950) and areference trace in air.Delay stageScan rangeFrequency resolutionAcquisition ratemechanical delay + fast voice coil25 .. 200 ps< 5 Ghz @ 200 ps scan range< 40 Ghz @ 25 ps scan rangePrecise scan: 20 s/spectrum, 100 ps delay, bandwidth4 Thz, peak dynamic range > 70 dB, 100 traces averaged;Fast scan: 50 ms/trace, 25 ps delay, bandwidth 3 Thz,peak dynamic range > 55 dB, no averaging;Intermediate settings possibleDynamic range (dB)8060402000 1 2 3 4 5 6Frequency (THz)Antenna packageTerahertz path lengthComputer interfaceComputer softwarecylindrical, Ø 30 mm,Integrated Si lens and SM/PM fiber pigtail20 .. 100 cm, adjustable via stationary delayethernetLabView control program, includedTerahertz spectrum of air with watervapor absorption lines. The peakdynamic range is 75 dB.order informationTeraFlashPulsed terahertz spectroscopy platform, with Femto-FErb 1560, 2x SM/PM fiber delivery, delay stage,two InGaAs photoconductive switches, laptop + software

Frequency-Domain TerahertzModular Product PackagesTOPTICA offers a set of modular product packages for frequency-domain terahertz spectroscopy. The Standard Package 850 and theTeraBeam 1550 consist of two widely-tunable DFB diode lasers with low-noise driver electronics, FPGA-based frequency control anda fiber-optic beam combiner. The High Power Extension includes a semiconductor or fiber amplifier, increasing the optical power to> 300 mW. The Phase Modulation Extension features two fiber stretchers for fast and accurate scanning of the terahertz phase. Last butnot least, the Spectroscopy Extension employs latest GaAs or InGaAs photomixer technology and optional terahertz optomechanics.All of these packages are available both at 850 nm and at 1550 nm. The packages can be combined and upgraded depending on therequirements of the experiment.Tunable DFB lasersNear-infrared distributed feedback (DFB) diodes are the lasers of choice to generate cw terahertz radiation. They unite high outputpower, narrow linewidth and mode-hop-free tuning up to 1000 GHz per diode. Responding to customer requirements, TOPTICA canselect a pair of diodes with a frequency difference tunable from 0 to 2 THz or from 1 to 3 THz. DFB lasers are available at the excitationwavelengths of both GaAs and InGaAs-based photomixers.The resolution of a cw terahertz spectrometer is only limited by the frequency stability of the lasers. In the case of DFB systems, thedifference frequency can be controlled with single-megahertz or even sub-megahertz precision. Consequently, cw terahertz techniquesare ideally suited for high-resolution spectroscopy (e.g., trace gas detection at low pressure).16 | www.toptica.com

Standard PackageHigh PowerExtensionPhase Mod.ExtensionBasic & CompleteSpectroscopy ExtensionAC Bias~DFB laser #1TXAmplifiersample positionDFB laser #2RXLock-inDetectionIncludesIncludesIncludesIncludesIncludes· 2 DFB diode lasers,· Semiconductor· Twin fiber· 2 GaAs· All components850 nm or 1550 nmor fiber amplifierstretcher,or InGaAsof Basic· Complete driver electronics· Fiber coupling at inputSM/PM fibersphotomixersSpectroscopy· FPGA-based frequency controland output· HV driver· PhotocurrentExtension· Fiber-optic beam combination· SM/PM fiber splitter,amplifier· 2 parabolic50:50 %· Softwaremirrors andinterfacemirror mounts· Precisionalignmentstagesfor photomixersDigital lock-in amplifierThe terahertz signal – the photocurrent in the receiver – resides in the pico- tonanoampère range. Recovering this faint signal requires lock-in detection: Theterahertz beam is periodically chopped and the readout circuit “looks” at the signalmodulation at the chopping frequency. The faster the chopping, the more efficientthe detection becomes. An elegant way to achieve kHz-rate chopping is to modulatethe bias voltage of the terahertz transmitter.In all of TOPTICA’s cw terahertz systems, the TeraControl unit acts as a digital lock-inamplifier for the terahertz signal. The FPGA-based module feeds an AC bias to thetransmitter and de-modulates the receiver photocurrent. In addition, the TeraControltunes the terahertz frequency by precisely adjusting the temperatures of both DFBlasers.TeraControl – digital lock-in modulewith USB interface.

Standard Package 850 / TeraBeam 1550DFB Lasers for cw Terahertz GenerationThe Standard Package offers the essential laser equipment for difference frequencygeneration in the terahertz range. It comprises two distributed feedback (DFB)lasers with built-in optical isolators, fiber-optic beam combination and low-noisedriver electronics. TOPTICA carefully selects the laser diodes with respect to theirmode-hop-free tuning range. Available at 850 nm and 1550 nm, the StandardPackage matches the excitation wavelengths of GaAs and InGaAs terahertzemitters, respectively.The TeraControl unit complements the package with computerized frequencytuning and lock-in detection of the terahertz photocurrent. A graphical interfaceconveniently sets or scans the terahertz frequency.Key features· Two DFB diode lasers with FPGAbasedfrequency control· Available wavelengths: 850 nm and1550 nm· Frequency accuracy 2 GHz absolute,10 MHz relativeThe workhorse for photomixingIn recent years, DFB diodes have developed into the workhorses for photomixing.DFB lasers offer robust mono-mode operation, wide continuous tuning andconvenient frequency control. The absence of alignment-sensitive componentsresults in a superior stability of output power and frequency.DFB lasers can be produced at virtually any near-infrared wavelength. The additionaladvantage of telecom-band diodes is their availability in highly integrated “butterfly”packages with miniaturized optics and a fiber pigtail. TOPTICA’s TeraBeam 1550uses these diodes.Applications· cw terahertz generation withGaAs photomixers (850 nm)· cw terahertz generation withInGaAs/InP photodiodes (1550 nm)DFB laser #1856Laser #1DFB laser #2PM fiber arrayWavelength (nm)854∆ν = 0 GHz∆ν = 2.1 THzSchematic of Standard Package.852Laser #20 10 20 30 40 50Temperature (°C)18 | www.toptica.comTemperature tuning of DFB lasers. The wavelengths of laser #1 and laser #2 match attemperatures of approximately 7 °C and 45 °C (shaded bar). By heating laser #1 andcooling laser #2, the difference frequency increases up to 2.1 THz. The TeraControlcalculates the precise temperature settings for any desired difference frequency.

Wide frequency tuning…The Standard Package contains thermally-tuned dFB diodes. The accessiblefrequency range depends on the tuning coefficient (25 GHz/K @ 850 nm, or 13 Hz/K @1550 nm) and the frequency offset between the two diodes. responding to customerrequirements, ToPTIcA provides special solutions when needed. For example, thescan range of the Standard Package 850 is 0 – 2 Thz by default, but can be changed to1 – 3 Thz if higher frequencies are preferred. Similarly, the scan range of the TeraBeam1550 is 0 – 1.2 Thz, or 1.0 – 2.2 Thz with customized diodes.1001000 GHz200 GHz… and precise frequency controlFor each laser diode used in the Standard Package or TeraBeam, ToPTIcA recordsprecise tuning curves (wavelength vs. temperature), which are stored in a lookup table.To tune to a desired terahertz frequency, the Teracontrol addresses the thermo-electriccoolers of both dFB lasers, employing two cascaded digital-analog converters with21-bit resolution per channel. The system achieves a 1 Ghz absolute accuracy of thedifference frequency and a resolution better than 10 mhz. The minimum frequency stepthen corresponds to a temperature change of only 200 μK!Spectral density (dB)-10-20-30-40-501525 1530 1535 1540 1545Wavelength (nm)Emission spectrum of theTeraBeam 1550, at differencefrequencies of 200 GHz and 1 THz.Specifications SYST THz STD / 850 TeraBeam 1550Lasers 2 x dL dFB To3 TeraBeam (2 butterfly-packaged DFBs)Laser power (fiber output) 2 x 50 mW 2 x 30 mWLaser wavelength* 853 + 855 nm 1546 + 1550 nmScan range per laser diode ± 1.3 nm ± 2.2 nmTHz scan range Typ. 0 – 1800 Ghz Typ. 0 – 1200 GhzTuning speedup to 100 Ghz/sFrequency accuracy2 Ghz absolute, < 10 mhz relativeFrequency stability (per laser)**Typ. 20 mhz rmS, 100 mhz p-p @ 5 hrsFrequency controlexternal Pc + Teracontrol Tc 110 (included)Optical isolation Included, 60 dB per laser Included, 80 dB per laserFiber couplingIncluded, 2x2 fiber arrayOperating temperature 15 – 30 °cDriver electronicsSyS dc 110 Twin dLLock-in amplifier Teracontrol Tc 110Computer interfaceuSBComputer softwarecontrol program with GuI, includedWavelength calibration filesProvided for both lasers* other ranges on request ** At constant environmental conditionsorder informationSYST THz STD / 850TeraBeam 1550Two-color dFB laser with driver electronics and FPGA-basedfrequency control, 853 + 855 nmcompact two-color dFB laser, including driver electronics and FPGA-basedfrequency control, 1546 + 1550 nm

High Power ExtensionLaser Amplifier with Fiber Input / OutputThe High Power Extension is the recommended tool for researchers who need extralaser photons to drive large-area terahertz emitters or to compensate for power losses inadditional modules (e.g., Phase Modulation Extension, or fiber taps).At 850 nm, the package comprises a BoosTA semiconductor amplifier with a fiber inputport and a 50:50 % fiber-splitter on the output side. The BoosTA amplifies the two-coloroutput of the Standard Package to more than 300 mW, while avoiding any cross-talkbetween the two lines. All of the spectral properties of the Standard Package remainunchanged.A 1550 nm version of the High Power Extension is also available, employing an Erbiumdopedfiber as gain medium.Key features· BoosTA: Semiconductor amplifierwith two SM/PM fiber outputs· 150 mW per output, @ 850 nm·1550 nm Erbium fiber amplifieravailable on requestSpecifications THz High Power / 850 THz High Power / 1550AmplifierWavelengthSemiconductor amplifier(BoosTA 850 L)853 + 855 nm, definedby Standard Package**Erbium fiber amplifier*Range 1535 .. 1565 nm,defined by TeraBeamApplications· Laser source for large-area terahertzemitters or emitter arrays· Recommended for systems withPhase Modulation ExtensionDifference frequency tuningDifference frequency resolutionFiber output powerCf. Standard Package or TeraBeamCf. Standard Package or TeraBeam2 x 150 mW250 mW .. 2000 mW(different models)Optical isolation Included, 60 dB IncludedFiber couplingIncluded, input + outputOutput fiber SM/PM splitter, 50:50 %DFB laser #1TaperedAmplifierElectronicsIntegrated into amplifier,+ external supplyIntegrated* Not required for Spectroscopy Extension / 1550 ** Customized wavelength ranges on requestDFB laser #210∆ν = 1.35 THz0Schematic of Standard Package (green)with High Power Extension (blue).Output spectrum of the BoosTA 850,as used in the High Power Extension.Spectral density (dB)-10-20-30-40-50840 845 850 855 860 865Wavelength (nm)Order informationTHz High Power / 850BoosTA amplifier with fiber input and fiberoutput1550 nm Erbium fiber amplifiers Please inquire for detailsNote: The High Power Extension requires a set of seed lasers(e.g., the Standard Package SYST THz STD / 850, or the TeraBeam 1550).

Phase Modulation ExtensionTwin Fiber Stretcher with HV Drivercw terahertz spectroscopy based on photomixing offers the attractive feature ofdetecting both amplitude and phase of the terahertz wave. Determining the phaserequires a modulation of the optical path length, or of the terahertz frequency. ThePhase Modulation Extension provides a fast and accurate technique to scan theterahertz phase by using a symmetric setup with two fiber stretchers wound aroundpiezo actuators. The twin-fiber concept not only doubles the modulation amplitude, butalso increases the thermal stability of the setup.The Phase Modulation Extension is available at 850 nm and 1550 nm. It perfectly fits theStandard Package 850 / TeraBeam 1550, and the Spectroscopy Extensions.Specifications THz Phase Mod / 850 THz Phase Mod / 1550ConceptWavelengthDifference frequency tuningDifference frequencyresolutionFibersTwin fiber stretcher with piezo actuators853 + 855 nm, definedby Standard Package*1546 + 1550 nm,defined by TeraBeamCf. Standard Package or TeraBeamCf. Standard Package or TeraBeam,Complete amplitude + phase informationat maximum resolution2 x 60 m, SM/PM fibersKey features· Fast and accurate modulation of theterahertz phase· Twin fiber stretcher with piezoactuators and HV driver· Path length modulation up to 3 mm@ 1 kHzApplications· High-resolution frequency-domainspectroscopy· Phase-sensitive terahertzmeasurements at fixed frequency(e.g., for imaging)Max. path length modulationHV driver3 mm @ 1 kHzIncludedSoftwareIncluded, part of control programDFB laser #1* Customized wavelength ranges on requestNormalized photocurrent1.00.50.0-0.5-1.0Delay stageFiber stretcher0 1 2 3 4Path length change (mm)Terahertz photocurrent, measuredwith fiber stretchers (red circles) or amechanical delay stage in the terahertzpath (black squares). The delay-stagescan deviates from a cosine fit due tostanding waves. The fiber-stretcherscan yields a perfect cosine curve.DFB laser #2Schematic of Standard Package (green)with Phase Modulation Extension (red).Order informationTHz Phase Mod / 850THz Phase Mod / 1550Twin fiber stretcher for terahertz phase modulation,850 nmTwin fiber stretcher for terahertz phase modulation,1550 nmNote: The Phase Modulation Extension requires a set of seed lasers(e.g., the Standard Package SYST THz STD / 850, or the TeraBeam 1550).Combination with the High Power Extension is recommended.www.toptica.com | 21

Photomixerscw Terahertz Generation with Leading-Edge TechnologyHaving teamed up with some of the world’s leading terahertz research institutes,TOPTICA is the only company worldwide that is able to offer top-quality GaAs andInGaAs photomixers. Both material systems have their own merits. GaAs photomixersprovide high bandwidths and a superior dynamic range when used in a coherenttransmitter-receiver configuration. InGaAs emitters, on the other hand, generatepower at record levels and take advantage of mature yet inexpensive 1.5 µm telecomtechnology.All of TOPTICA’s photomixer modules come equipped with a Silicon lens, an electricconnector and SM/PM fiber pigtail. The all-fiber design enables an easy and flexibleintegration into any terahertz assembly.Key features· GaAs (850 nm) and InGaAs(1550 nm) photomixers· Fully-packaged modules withSM/PM fiber pigtail· Signal-to-noise ratio up to 80 dBApplications· High-resolution terahertzspectroscopy· Combustion analysis, semiconductorstudies, non-destructive testingHighest bandwidths with GaAs photomixersBased on a planar structure, GaAs photomixers comprise an interdigitated fingerstructure at the center and a surrounding broadband antenna. The bandgap of thesemiconductor calls for excitation wavelengths below 870 nm. To efficiently generateterahertz radiation, the chip design relies on “defect engineering” techniques: Lowtemperaturegrowth, the integration of ErAs nanoclusters or ion bombardment reducesthe recombination times of the photoelectrons.TOPTICA’s GaAs photomixers achieve an outstanding bandwidth of 3 THz and dynamicranges as high as 80 dB at 100 GHz, or 60 dB at 1000 GHz.Terahertz power (µW)1010.10.011E-31E-40 500 1000 1500 2000Frequency (GHz)2µmlight300nm20µmmetalp-contact(i) absorbern-contactwaveguideOutput power of an InGaAs photodiodeemitter.Cross-section of an InGaAs photodiodeemitter with integrated waveguide.(Fraunhofer Heinrich-Hertz Institute,Berlin / Germany)2800Dynamic range (dB)604020Integration time 300 msIntegration time 2.6 ms00 500 1000 1500 2000Frequency (GHz)V −V+Optical beatMetallizationActive layerV+ V− V+V−Semi-insulating substratePhotocurrent (mA)-2-4Laser power-60 mW10 mW-820 mW30 mW-10-2.0 -1.5 -1.0 -0.5 0.0 0.5 1.0DC bias (V)Dynamic range of GaAs photomixers,used in a coherent emitter-receiverconfiguration. The dips are absorptionlines of water vapor.Top view (left) and cross section(right) of a planar photomixer withinterdigitated finger structure. V+ andV- denote the bias voltage.Photocurrent vs. bias voltage of anInGaAs photodiode emitter.

High power from InGaAs emittersInGaAs-based terahertz emitters comprise ultrafast p-i-n photodiodes, with an intrinsiclayer embedded between p-doped and n-doped semiconductor layers. The laser lightis coupled into the intrinsic layer from an underlying waveguide structure. In this design,the extended absorption length leads to highly-efficient terahertz generation.InGaAs has a semiconductor bandgap of 1.68 µm and telecom lasers at 1.5 µm arethus a perfect match. The combination of TOPTICA’s TeraBeam laser and InGaAsemitter/detector modules presents a highly-compact terahertz platform, and achievespower levels up to 10 µW.Specifications #EK-000685 #EK-000724 / #EK-000725Semiconductor material GaAs InGaAs on InPWavelength 853 + 855 nm 1546 + 1550 nmEmitterPhotomixerWaveguide-integratedp-i-n photodiodeReceiver Photomixer PhotomixerAntenna type Log-spiral Bow-tieEmitter / receiver bandwidth* > 3 THz > 2 THzTerahertz power (typ.)Terahertz dynamic range(@ 300 ms integration time)PackageRecommended operatingconditions2 µW @ 100 GHz0.3 µW @ 500 GHz80 dB @ 100 GHz70 dB @ 500 GHzCylindrical, Ø 1”,integrated Si lens & SM/PM fiber pigtailLaser power < 50 mWBias ± 10 V4 µW @ 100 GHz0.5 µW @ 500 GHz70 dB @ 100 GHz50 dB @ 500 GHzCylindrical, Ø 30 mm,integrated Si lens & SM/PM fiber pigtailLaser power 20 mWBias 0 / -1.5 VKey advantages High bandwidth, high dynamic range Compact laser unit, low cost* Tuning range of lasers may differOrder information850 nm#EK-0006851550 nm#EK-000724#EK-000725GaAs photomixer for cw terahertz generation and detection, with log-spiral antenna andSM/PM fiber pigtailInGaAs/InP based waveguide-integrated photodiode for cw terahertz generation, withbow-tie antenna and SM/PM fiber pigtailInGaAs/InP based photoconductor for cw terahertz detection,with bow-tie antenna andSM/PM fiber pigtailNote: The photomixers are available as individual modules or as part of the Spectroscopy Extension (p. 25).Operation requires a set of seed lasers (e.g., the Standard Package SYST THz STD / 850, or the TeraBeam 1550).www.toptica.com | 23

Spectroscopy ExtensionBasic and complete VersionKey features· Available for 850 nm (GaAs) and1550 nm (InGaAs) technology· Basic version: 2 photomixers withlow-noise transimpedance amplifier· complete version with additionaloptomechanicsApplications· high-resolution spectroscopy· combustion analysis, semiconductorstudies, non-destructive testingThe Spectroscopy extension complements the laser packages and provides theessential equipment to start a frequency-domain terahertz experiment. employingthe latest GaAs or InGaAs photomixer technology, the Spectroscopy extension hastwo versions with different levels of integration. The basic version, conceived forresearchers who prefer to design their own terahertz beam path, features two fiberpigtailedphotomixers and a transimpedance amplifier. The second, or completeversion, additionally includes two positioning stages for the photomixers and twooff-axis parabolic mirrors to collimate and refocus the terahertz beam. The entiresystem is conveniently controlled from a standard laptop or Pc.AC Bias~DFB laser #1TXsample positionDFB laser #2RXLock-inDetectionStandard Package (green) withBasic (bright yellow) and CompleteSpectroscopy Extensions (yellow).Basic Spectroscopy ExtensionComplete Spectroscopy ExtensionSpecifications Spectroscopy Extension / Basic Spectroscopy Extension / CompletePhotomixersTransmitter and receiver module included(GaAs: 2x #eK-000685; InGaAs: #eK-000724 + #eK-000725)Lock-in amplifier Teracontrol, part of Standard Package 850 / TeraBeam 1550Transimpedance amplifierPdA-S, included2 xyz stages for photomixers -- Included2 off-axis parabolic mirrors -- IncludedManual delay stage -- IncludedMotorized delay stageno; please see Phase modulation extensionOptical rails -- IncludedComputer softwarecontrol program with GuI, includedorder informationTHz Spec Basic / 850 Spectroscopy extension, basic version, 850 nmTHz Spec Compl / 850Spectroscopy extension, complete version, 850 nmTHz Spec Basic / 1550 Spectroscopy extension, basic version, 1550 nmTHz Spec Compl / 1550Spectroscopy extension, complete version, 1550 nmnote: The Spectroscopy extension requires a set of seed lasers (e.g., the Standard Package SyST Thz STd / 850,or the TeraBeam 1550). It fits the Phase Modulation Extensions THz Phase Mod / 850 and THz Phase Mod / 1550.24 | www.toptica.com

Customized SolutionsInnovative Answers to “crazy” IdeasSolutions from the specialistsTerahertz science is a vibrant and exciting field of research. The number of applications isgrowing steadily, and so are the requirements on the utilized laser systems. Before long,a “Standard Package” may need to be modified if photomixers must be cooled to liquidheliumtemperatures or terahertz frequencies outside the lasers’ tuning range are desired.A “complete Spectroscopy extension” might even call for further completion if the beamis to be focused onto a microscopic sample.ToPTIcA’s product specialists have many years of hands-on experience with diodelasers, electronics and terahertz applications. They respond quickly and flexibly to yourrequirements.Tuning-range extensionsThe tuning range of the dFB lasers usually limits the frequency span of a cw terahertzspectrum. Adding a third diode laser greatly enhances the accessible frequency range.With carefully selected dFB laser wavelengths, ToPTIcA has pushed the bandwidth of a1550 nm TeraBeam + Spectroscopy extension to beyond 2 Thz.other “exotic” applications might require seed wavelengths other than 850 nm or 1550nm: for example, for research on novel photomixer materials, or for cryogenic experiments,where the temperature-induced change of the photomixers’ band-gap must be taken intoaccount. These systems may require a fully customized laser solution, but we at ToPTIcAlook forward to meeting the challenge!Megahertz resolution, focused beamsultimate spectral resolution is achieved by combining the dFB lasers of the StandardPackage with ToPTIcA’s patented iScan quadrature interferometer. The frequency ofeach laser is adjusted with an accuracy of 1 mhz. This translates directly into the resolutionof the terahertz signal, making the cw terahertz platforms well-suited for even the mostchallenging measurement tasks in low-pressure gas spectroscopy.If highest spatial (rather than spectral) resolution is required, ToPTIcA provides customizedoptics assemblies with a focused terahertz beam. dedicated mechanics include a slide barwith kinematic mounts, allowing the user to switch between transmission and reflectionmodemeasurements.Wavelength (nm)85785685585433 sec1.2 THz0 20 40 60 80 100 120 140Time (s)Precise linear frequency scanning.Key features· Flexible realization of customizeddesigns· Terahertz optics or 3-laser setupswith extended tuning range· Interferometric frequency controlwith single-mhz resolutionApplications· Precision spectroscopy(e.g., gas-sensing at low pressure)· Transmission/reflectionmeasurements with focusedterahertz beamSlide barCompact module for terahertzmeasurements in transmission (rightbeam path) and reflection mode (leftbeam path).Twin iScan for precise frequencycontrol.www.toptica.com | 25

TeraScan 850 / 1550ToPSellers for Frequency-domain SpectroscopyKey features· Preconfigured systems with high-endGaAs or InGaAs photomixers· highest bandwidth and best dynamicrange: TeraScan 850· most compact and inexpensivespectroscopy platform: TeraScan1550TOPTICA’s TeraScan systems are “TOPSeller” configurations, designed for some of the mostcommon frequency-domain terahertz applications. The TeraScan 850 consists of StandardPackage 850 + Basic Spectroscopy extension 850. Based on GaAs photomixer technology, itoffers an outstanding bandwidth and maximum dynamic range. The TeraScan 1550 unites theTeraBeam laser and the InGaAs terahertz emitters/receivers of the Basic Spectroscopy extension1550. This assembly provides the most compact solution for cw terahertz spectroscopy. Bothsystems feature an intuitive software interface and ToPTIcA’s proprietary Teracontrol module forcomputerized frequency tuning and terahertz data acquisition.Applications· Well-established starter package forcw terahertz spectroscopy· Base unit for system integratorsSpecifications TeraScan 850 TeraScan 1550ComponentsLasersStandard Package 850& Basic Spectroscopyextension 8502 x dL dFB To3TeraBeam 1550& Basic Spectroscopyextension 1550TeraBeam, including2 butterfly-packaged DFBdiodesWavelength 853 + 855 nm 1546 + 1550 nmTerahertz emitter GaAs photomixer InGaAs photodiodeTerahertz receiver GaAs photomixer InGaAs photomixerAntenna type Log-spiral Bow-tieAntenna packagecylindrical, Ø 1”,SM/PM fiber pigtailcylindrical, Ø 30 mm,SM/PM fiber pigtailTerahertz power (typ.)2 μW @ 100 Ghz0.3 μW @ 500 Ghz4 μW @ 100 Ghz0.5 μW @ 500 GhzDFB laser #1AC Bias~TXTerahertz dynamicrange (@ 300 ms lock-intime)80 dB @ 100 Ghz70 dB @ 500 Ghz70 dB @ 100 Ghz50 dB @ 500 GhzTHz scan range Typ. 0 – 1800 Ghz Typ. 0 – 1200 GhzTuning speedup to 100 Ghz/sDFB laser #2Lock-inDetectionRXFrequency accuracyFrequency control2 Ghz absolute< 10 mhz relativeexternal Pc + Teracontrol Tc 110 (included)TOPTICA’s TeraScan systemsconsist of Standard Package (green)and Basic Spectroscopy Extension(bright yellow).order informationTeraScan 850TeraScan 1550Two-color dFB laser, 853 + 855 nm, with driver electronics,FPGA-based frequency control, and two GaAs photomixerscompact two-color dFB laser (TeraBeam 1550), with driver electronics,FPGA-based frequency control, and two InGaAs photomixers26 | www.toptica.com

Take a Look InsideTerahertz radiation is unique in offering the ability to look intotraditionally opaque materials, or to identify chemical substances bytheir spectroscopic fi ngerprint. Terahertz instrumentation is alreadyfound in homeland security, quality control, non-destructive testing andadvanced research.And quite often you will fi nd TOPTICA’s technology inside.Terahertz @ TOPTICATime-domain systemsfor high-bandwidth spectroscopyNew: TeraFlash – 4 THz bandwidth, 20 traces/secFrequency-domain systemsfor high-resolution spectroscopyTOPSellers:TeraScan 850 and TeraScan 1550 –10 MHz resolution, > 80 dB SNRA Passion for Precision.www.toptica.com/terahertz

distributorsBr-043 B 2012-10Australia & New ZealandLastek Pty. Ltd.Thebarton CampusUniversity of Adelaide10 Reid Street5031 Thebarton, SAAustraliaPhone: +61 8 8443 8668Fax: +61 8 8443 8427sales@lastek.com.auwww.lastek.com.auChinaUniversal (Hong Kong)Technology Co. Ltd.Room 615-619Capital Group PlazaNo. 6 Chaoyangmen BeidajieBeijing 100027, P.R. ChinaPhone: +86 10 8528 3377Fax: +86 10 8528 3344oe@universalhkco.com.cnwww.universalhkco.com.cn(Offices: Beijing, Shanghai)FranceOpton Laser InternationalParc Club d‘Orsay Université29, rue Jean RostandF-91893 Orsay Cedex, FrancePhone: +33 1 6941 0405Fax: +33 1 6941 3290ventes@optonlaser.comwww.optonlaser.comIndiaSimco Global Technology &Systems Ltd.Simco House (Head Office)14 Bhawani KunjBehind Sector D-II Vasant Kunj110017 New Delhi, IndiaPhone: +91 11 2689 9867Fax: +91 11 2612 4461admin@simcogroup.inwww.simco-groups.com(Offices: New Delhi, Bengaluru,Kolkata, Mumbai)IsraelLahat Technologies Ltd.Teradion Industrial ZoneM.P. Misgav, 20179, IsraelPhone: +972 4 999 0151Fax: +972 4 999 0826sales@lahat.co.ilwww.lahat.co.ilJapanINDECO, INC.1-11-14, Kasuga, Bunkyo-kuTokyo 112-0003, JapanPhone: +81 3 3818 4011Fax: +81 3 3818 4015ind@indeco.jpwww.indeco.jp(Offices: Tokyo, Osaka)KoreaJINSUNG LASER#535-5, Bongmyung-DongYusung-GuHanjin Officetel Rm# 1016Daejeon, 305-301, South KoreaPhone: +82 42 823 5300Fax: +82 42 823 7447sales@jinsunglaser.comwww.jinsunglaser.comRussiaEuroLase Ltd.Gubkina 14-80117312 MoscowRussiabagratashvili@mail.ruwww.eurolase.ruSingapore / MalaysiaPrecision Technologies Pte Ltd211 Henderson Road # 13-02Henderson Industrial ParkSingapore 159552Phone: +65 6273 4573Fax: +65 6273 8898precision@pretech.com.sgwww.pretech.com.sgTaiwanSLEO Photonics Co. Ltd.6F, No. 2, Lane 74An-der StreettHsin Tien City, Taipei CountyTaiwan 231, R.O.C.Phone: +886 2 2211 5408Fax: +886 2 2211 5401sleo.jimmy@msa.hinet.netLuxton Inc.F4, No. 2, Technology Road V,Hsinchu Science Park,Hsinchu 30078, TaiwanPhone: +886 3 666-2097Fax: +886 3 666-2124service@luxton.com.twwww.luxton.com.twTurkeyCS Analytical LaboratoryEquipments Ltd.Ergin Sokak No: 27/506580 Mebusevier - TandoganAnkara, TurkeyPhone: +90 312 223 0302Fax: +90 312 223 0305can@csanalitik.com.trwww.csanalitik.com.trUnited Kingdom & IrelandHoward Potter Laser TechnologyUnit 4H Lansbury EstateWoking, Surrey, UK, GU21 2EPGreat BritainPhone: +44 1483 799 030Fax: +44 1483 799 076howard.potter@toptica.comwww.howardpotter.co.ukUSA & Canada; MexicoTOPTICA Photonics, Inc.1286 Blossom DriveVictor/Rochester, NY 14564U.S.A.Phone: +1 585 657 6663Fax: +1 877 277 9897sales@toptica.comwww.toptica.com(Offices: Rochester,Atlanta, San Jose)Every other countrynot listed above:TOPTICA Photonics AGLochhamer Schlag 19D-82166 Graefelfing/MunichGermanyPhone: +49 89 85837-0Fax: +49 89 85837-200sales@toptica.comwww.toptica.comTOPTICA Photonics AGLochhamer Schlag 19D-82166 Graefelfing/MunichGermanyPhone: +49 89 85837-0Fax: +49 89 85837-200info@toptica.comwww.toptica.comTOPTICA Photonics, Inc.1286 Blossom DriveVictor / Rochester, NY 14564U.S.A.Phone: +1 585 657 6663Fax: +1 877 277 9897sales@toptica.comwww.toptica.com