Time-Domain Terahertz - Toptica

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