Time-Domain Terahertz - Toptica

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