Imaging of beams from TDS and FDS spectroscopy systems

Our terahertz imaging camera is a perfect tool for TDS and FDS beam profile measurement which was proved jointly by TERASENSE and TOPTICA researchers in the course of our R&D project followed by technical meeting held at TOPTICA’s headquarters in Munich, March 19-20, 2015.Screen Shot 2015-04-15 at 14.59.01
We are absolutely confident, the results obtained in the course of this mutually enriching collaboration mark the advent of an entirely new era in the development of TDS and FDS systems – now reinforced with TERASENSE imagers.

Terahertz time-domain spectroscopy (THz-TDS)

Terahertz time-domain spectroscopy is a spectroscopic technique in which the properties of a material are probed with short pulses of terahertz radiation. The generation and detection scheme is sensitive to the sample material’s effect on both the amplitude and the phase of the terahertz radiation. Pulsed terahertz radiation is generated by photoconductive switches (GaAs or InGaAs/InP) irradiated by femtosecond lasers. At the end, a fact Fourier transform of terahertz amplitude produces the terahertz spectrum in the frequency range 0.1 – 5 THz.

Screen Shot

Test of TeraSense camera operation with TDS system

Screen ShotScreen Shot
  • 50 GHz – 0.7 THz frequency range
  • 1.5 x 1.5 mm2 pixel size
  • 1 nW√Hz noise equivalent power
  • Up to 50 frames per second
  • 16×16, 32×32, 64×64 total pixel models
  • Fiber-coupled InGaAs photoconductive switches
  • 0.1 – 5 THz bandwidth
  • >90 dB peak dynamic range
  • Average power 25 uW
  • 100 MHz pulse repetition rate
Screen Shot 2015-04-15 at 16.55.21

Terahertz frequency-domain spectroscopy (THz-FDS)

Terahertz frequency-domain spectroscopy is a spectroscopic technique in which the properties of a material are probed with continuous-wave (cw) terahertz radiation. The radiation is obtained by optical heterodyning in high-bandwidth photoconductors: the output of two cw lasers converts into terahertz radiation, exactly at the difference frequency of the lasers. The photomixer is represented by a microscopic metal-semiconductor-metal structure. Applying a bias voltage to the semiconductor structure then generates a photocurrent that oscillates at the beat frequency. The output frequency spans from 50 GHz up to 1.5 THz.

Screen Shot 2015-04-16 at 10.37.54

Test of TeraSense camera operation with TDS system

Screen Shot 2015-04-16 at 10.24.30
  • 50 GHz – 0.7 THz frequency range
  • 1.5 x 1.5 mm2 pixel size
  • 1 nW√Hz noise equivalent power
  • Up to 50 frames per second
  • 16×16, 32×32, 64×64 total pixel models
Screen Shot 2015-04-16 at 10.24.58
  • InGaAs photomixer with bow-tie antenna
  • 0 – 1.2 THz THz scan range
  • Frequency accuracy 2 GHz absolute, 10 MHz relative
  • Power 48 uW (100 GHz), 4 uW (500 GHz)
  • Up tp 100 GHz/s tuning rate
Screen ShotScreen Shot 2015-04-16 at 10.59.55

Have any questions? Please contact us.