THz成像相机首次用于THz时域光谱和THz频域光谱系统

THz时域光谱系统（THz-TDS）

Terahertz time-domain spectroscopy is a spectroscopic technique in which the properties of a material are probed with short pulses of THz 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) or nonlinear media 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.

We are glad to announce that our partners from AVESTA succeeded to produce a multistage chirped-pulse amplification laser system (1.25 μm wavelength) which was used to set a world record in a high power THz pulse generation. Hauri group reports on high-field terahertz transients with 0.9-mJ pulse energy produced in a 400??mm2 partitioned organic crystal by optical rectification of a 30-mJ laser pulse centered at 1.25 μm wavelength. The phase-locked single-cycle terahertz pulses cover the hard-to-access low-frequency range between 0.1 and 5 THz and carry peak fields of more than 42 MV/cm and 14 Tesla with the potential to reach over 80 MV/cm by choosing appropriate focusing optics. The scheme based on a Cr:Mg2SiO4 laser offers a high conversion efficiency of 3% using uncooled organic crystal. The collimated pump laser configuration provides excellent terahertz focusing conditions.

The high-energy THz pulsed generator TERA-AX by AVESTA partners helped Terasense to precisely measure the ultrafast response time of our proprietary passive THz detector. Such short response time opens up the possibility to observe and resolve ultrafast transient processes in many THz applications.

THz频域光谱系统（THz-FDS）

erahertz 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.

THz相机和THz光源参数:

测试结果：

Valuable scientific achievements were obtained jointly by TERASENSE and TOPTICA researchers in the course of our R&D project followed by technical meeting held at TOPTICA's headquarters at Munich, March TERASENSE highly appreciates the efforts made by Dr. Anselm Deninger, TOPTICA Product Manager in creating friendly environment for the meeting. The contribution made by Mr. Wolfgang Gruber, SEMIC RF Electronic GmbH in arrangement and making it all happen can hardly be overestimated and deserve special thanks. 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.