T-SPEC Real-Time Terahertz Spectrometer太赫兹实时光谱仪
Features
Wide spectral range up to 5 THz
High dynamic range >90 dB @ 0.4 THz
Real-time data acquisition up to 10 spectra/s
Excellent spectral resolution up to 1 GHz
“No bearing” design of fast delay line – virtually unlimited lifetime
Transmission, reflection, optical pump THz probe modes
High spatial resolution THz imaging
Complete PC control
User-friendly software
Applications
Chemical material characterization
Carrier lifetime and mobility in semiconductors
Dielectric properties and complex refractive index
Metamaterials investigation
Medical and biological nondestructive research
Thickness measurements
Description
Real-time Terahertz Spectrometer offered by TERAVIL is a powerful tool for investigative applications of pulsed terahertz waves. With simple and robust design, it is easy-to-use and adaptable to individual requirements.
The unique design of microstrip photoconductive antenna fabricated on low-temperature grown GaAs substrate ensures broadband spectral coverage and high dynamic range. The system is designed with two delay lines: fast and slow. Fast scan line allows real time data acquisition with 10 spectra/s speed and 116 ps time window. Average of collected spectra can increase dynamic range up to 90 dB at pulse maximum and extend spectral range up to 5 THz. Additional slow delay line allows combination of multiple time windows; thus spectrometer obtains excellent spectral resolution up to 1 GHz. The fast scan line is designed without bearings and uses a magnetically coupled drive which makes it extremely reliable and significantly extends the lifetime.
T-SPEC spectrometer has housing with mounted gas inlets. It can be used as purging box, when experiment requires special environmental conditions, like nitrogen or dried air. The spacious sample area allows easy integration of additional equipment, like cryostat or heater.
On a special demand we can provide the integration of such equipment, ensuring good fit, spectrometer box sealing, vibration isolation and operation automation.
Spectrometer is equipped with two standard spectroscopy modules for transmission and reflection configurations. Each module contains motorized sample manipulator. This allows measurements of multiple samples one by one, without physical access to the spectrometer. Reflection module has convenient vertical architecture, where THz beams reaches the sample from bottom and reflects backwards. The measured samples can be replaced quickly just by laying them down on the sample holder. No adjustment is needed either when changing samples or when changing modules.
Our T-SPEC series spectrometer is the perfect choice for broadband THz imaging. It allows scan of up to 25×25 mm sample with spatial resolution of approx. 1 mm. Measurements contain information about the target, revealing both structural and spectroscopic information.
T-SPEC spectrometer can be adopted for optical pump THz probe measurements. This allows investigation of carrier dynamics in semiconductors, nanocrystals, and other materials. One part of additional optics is placed inside spectrometer; another part with delay line is mounted on T-SPEC outside wall. Measurement can be done up to 1 ns with temporal resolution of approx. 0.5 ps.
In case when customer has own 780 nm or 1060 nm fs-laser, TERAVIL could provide T-SPEC spectrometer adopted to that laser. The optical and THz beam paths will be pre-aligned. Therefore, it is only required to feed the laser beam into the optical setup of the spectrometer. Laser must satisfy following parameters: pulse duration ~100 fs, repetition rate in range 10-100 MHz.
Specifications
| |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Performance & Images
 |  |
Typical performance of T-SPEC series Real-time THz Spectrometer (measured in ambient atmosphere)
Optical layout of THz spectrometer T-SPEC series for optical pump THz probe measurements
T-SPEC 1000 without top cover
T-SPEC spectroscopy modules: reflection geometry (left) and transmission geometry (right)
THz Spectroscopy Kit
Description
TERAVIL “THz spectroscopy kit” contains all the components necessary to build THz-TDS system. The standard kit consists of photoconductive antenna THz emitter and detector, pump laser beam guiding optics, motorized delay line with controller, THz beam guiding optics, sample holder and THz registering system TRS-16 with fast delay line. All components are assembled on the baseplate of 60×80 or 80x80 cm dimensions. THz spectroscopy kit includes powerful system control, data acquisition and analysis software package.
Example of optical layout of THz spectroscopy kit in transmission configuration
The optical and THz beam paths will be pre-aligned. Therefore, it is only required to feed the laser beam into the optical setup of the spectrometer. Laser must satisfy following parameters: pulse duration ~100 fs, repetition rate in range 10-100 MHz, laser wavelength ~780 nm or ~1060 nm.
Four standard configurations are available, optimized for transmission, reflection, imaging or optical pump-THz probe measurement. All can be easily interchanged and modified. Any other optional configuration can be ordered initially or as a future upgrade.
“THz spectroscopy kit” could include few configurations in one. We could construct hybrid kit containing free space THz emitter/detector and fiber coupled. As an option goniometer stage can be supplied. This inexpensive module allows operation in multiple most common geometries, including transmission and tunable angle reflection from approx. 18.5° up to 90°. It also can be used for unique THz scattering experiments, because sample and detector angles can be changed independently.
Configuration for investigations of THz emission from various semiconductors in reflection or transmission mode could be included into kit.
Our engineers have more than ten years experience in engineering of THz setups. We are open for discussions and are happy to tailor kit to your needs.
Few examples of our installed kits
THz kit containing free space transmission setup, fiber coupled THz emitter/detector mounted on goniometer stage and configuration for THz surface emission
Optical pump-THz probe setup with four mirror transmission configuration
LIDAR operating in terahertz range to scan remote objects at 7 m distance
Optical pump-THz probe setup with integrated cryostat
Four mirror transmission configuration and purging box
Four mirror transmission configuration and 0 angle reflection module
Transmission and 0 angle reflection setup. Two detectors are used: one for transmitted THz signal registration, second for reflected
Transmission setup with HDPE lenses and sample holder on XY stage
太赫兹产品系列：
Open access THz laboratory
Optical pump - THz probe experiments
For the measurement of the electrical transport dynamics in the semiconductors, nanocrystals, and other materials on the picoseconds time scale, optical pump - THz probe technique can be used. THz radiation emitter and detector for the measurements are made as dipole antenna on LTG GaAs layer and are activated by the parts of Ti:sapphire laser beam. The third part of the same laser beam is used for the photoexcitation of the samples. Excitation levels up to 100 nJ/cm2 can be achieved; excitation levels up to 2 µJ/cm2 can be achieved using the metallic aperture with the diameter of 300 µm. Both - optical pump and THz probe beams overlap at this aperture.
Fig. 1 Optical pump THz probe experiment scheme.
The dependence of the THz transient signal at its maximum amplitude is measured at different delays of the optical pump pulse. Fig. 5 shows the temporal dynamics of the optical pump induced change in the transmittance at THz frequencies measured by this technique.
Fig. 2 Electrical transport Dynamics of the different GaAs samples.
Temporal resolution of this experiment is determined by the response of the detector measuring THz transients and is approximately equal to 1-1.5 ps. Maximum temporal range of the experimental setup is 600 ps (limited by the optical delay line length). The measurements can be done in transmission or reflection geometry and wide temperature range (from 10 to 300K).
THz Spectroscopy
Electromagnetic radiation in the terahertz frequency range (0.1 THz - 4 THz) has many important applications in the areas of spectroscopy, detection, and security.
Fig. 3 THz-TDS spectrometer "T-Spec".
In the "T-Spec" spectrometer (Fig. 1) few-cycle THz pulses are generated by exciting an electrically biased photoconductive dipole with an ultrafast laser pulse (<100 fs). The resulting photo-generated current responds on a picosecond timescale and leads to THz electromagnetic pulse radiation. High-resistivity Si hyperhemispherical lenses are used to improve the outcoupling efficiency of the THz radiation generated in the GaAs substrate of the photoconducting dipoles into the free space. Additionally, off-axis parabolic mirrors are used to focus THz radiation to the sample.
Fig. 4 Transmission and reflection modules.
"T-Spec" has two modules: transmission (Fig. 2a) and 0 angle reflection (Fig. 2b). Exchange of the modules takes no more than a few seconds and no additional alignment is needed. On both modules, XY stage, with scanning range of 25x25mm, can be used for imaging experiments. FFT spectrum of the measured THz pulse transients can reach up to 4 THz (Fig. 3). Powders and liquids can be characterized in both configurations using standard optical spectroscopy cells.
Fig. 5 Comparison of the FFT spectrum in transmission and reflection configurations.
Conditions
The use of the instruments described above is free of charge under the self-service basis.
In case of the experiments on request 100 EUR/day charge will apply (one working day is minimum). All the conditions of the experiment and the results will be briefly reported (3-10 p. report). Number of the samples measured per one working day depends on the experiment, for example: 1 sample per day if optical pump-THz probe measurement is done in low temperature (10-270 K) or 5-7 samples if in room temperature; for spectroscopy experiments, measurement speed is approximately 5 samples/hour. Imaging speed depends on the number of pixels. For example 10 000 pixels image of the shaving blade (Fig. 1 software window) can be done in approximately 2 hours (time includes sample preparation, positioning etc.). For special experimental conditions please contact us directly.
嗡 哇苏
达咧司哇哈
全国服务热线：
185-021-93480
扫一扫
关注我们
