Tera-AX. High-Intensity Terahertz Generator
|THz output specifications|
|THz pulse energy||up to 1* uJ|
|Optical-to-THz conversion efficiency||up to 0.1%|
|THz pulse duration||0.5-1 ps|
|Spectral frequency range||broadband, 0.5-2.5 THz|
|THz beam divergence||45 mrad in vertical direction;
100 mrad in horizontal direction
|EO-AX THz time-domain spectrometer parameters (optional)|
|Frequency resolution||30 GHz|
|Temporal scan range||180 ps|
|Data acquisition and analysis||Windows PC software included; USB 2.0 interface|
|Possible ranges of optical pump specifications**|
|Central wavelength||780-820 nm|
|Pulse duration||50-500 fs, transform-limited pulse|
|Pulse energy||0.5-5 mJ|
|Repetition rate||10 Hz - 10 kHz|
|Beam diameter (at 1/e^2 level)||>9 mm|
|Pulse energy stability (rms)||<1%|
|Environmental and utility specifications|
|Relative humidity||<60%, non-condensing|
|Voltage (for EO-AX and Tera-AX-Cryo)||single-phase; 100-240 VAC; 50/60 Hz|
|Max. power consumption (for EO-AX and Tera-AX-Cryo w. vacuum conditioning)||<2 kW|
|Vacuum port (for Tera-AX-Cryo)||KF16|
|Operational pressure requirement (for Tera-AX-Cryo)||<10-5 mbar|
|Liquid nitrogen capacity (for Tera-AX-Cryo)||1 litre|
|Tera-AX||600 x 300 x 200 mm|
|Tera-AX-Cryo||930 x 630 x 480 mm|
|* - obtained with the REUS-3m1k Ti:S pump laser with output specs: 1 kHz, 2 mJ, 100 fs FTL, 800 nm CWL;
** - each system is tailored to a certain set of optical pump specifications, please indicate complete pump laser specification with your request so we can estimate Tera-AX THz output values;
THz science has recently come to a new era: field magnitude of an order of MV/cm has been reached, allowing to study THz nonlinear carrier dynamics in semiconductors, THz acceleration of electrons, electron-packet sampling and many other applications. In order to provide a robust tool for studying nonlinear THz physics and THz imaging, we developed a source of a high-field pulsed THz radiation in the range 0.5-3 THz. The Tera-AX generator based on phase-matched optical rectification in MgO:LiNbO3 crystal and can be used with commercial femtosecond Ti:Sapphire regenerative amplifiers such as the REUS series by AVESTA Ltd.
A modification of the Tera-AX system with a cryogenically-cooled lithium niobate crystal is also available. In the Tera-AX-Cryo version, the crystal is placed on a cold plate of a liquid-nitrogen filled cryostat. Cooling the generator crystal drastically decreases its THz absorption and allows to achieve outstanding optical-to THz conversion efficiency of up to 10-3 level and improves the long-term stability of conversion efficiency. The optical scheme of Tera-AX-Cryo is pre-adjusted for use at temperature of 93 K, but it can be easily optimized for use at room temperature.
As an option, in both the Tera-AX and the Tera-AX-Cryo, a larger-aperture MgO:LiNbO3 crystal can be utilized in order to accept higher-energy optical pump pulses (we recommend this option for energies of femtosecond pump pulses higher than 2 mJ).
The Tera-AX or the Tera-AX-Cryo generators can either be used as stand-alone units, providing a collimated THz output beam, or as a part of a THz transmission spectrometer equipped with an electro-optical sampling detection (EO TDS). This allows to obtain the temporal profiles of THz field passing the sample under study and get the information on its complex dielectric function in range 0.5-2.5 THz. An optical pump-terahertz probe modification (OPTP) of the optical layout is available upon request.
The complete system may contain the following components:
- the Tera-AX optical unit with THz emitter based on optical rectification in MgO:LiNbO3 crystal with output parabolic mirror;
- the Tera-AX-Cryo optical unit with cryo-cooled THz emitter based on optical rectification in MgO:LiNbO3 crystal;
- (optional) the EO-AX terahertz time-domain spectrometer that includes:
1) 3 parabolic mirrors for focusing the THz beam in the sample;
2) Electrooptical detector with lock-in amplifier or highly-sensitive peak detector and digitizer (depending on the repetition rate of the regenerative amplifier) with USB interface;
3) Optical chopper;
4) Windows acquisition and analysis software.
The full system is supplied on main breadboard with a cover box that can be purged with nitrogen if necessary.
-Cryo: cryo-cooled version with increased efficiency
-OPTP: 800-nm pump - THz probe sample setup modification
-LA: large-aperture version for higher pump levels and higher output pulse energy
Note: some of the modifications and options may be combined.
Q: Can you supply a complete system with Ti:S ultrafast pump laser, high-energy THz emitter and time-domain spectrometer unit?|
A: Yes, we can supply a complete system. The pump laser may be chosen from the REUS family of Ti:S amplifier systems.
Q: Can we use our own Ti:S amplifier as a pump source for the Tera-AX/Tera-AX-Cryo?
A: Yes, you can. Please indicate the specifications/brand/model of your amplifier system with your request.
Avesta is participating in Ultrafast Phenomena 2018 conference and tabletop exhibition in Hamburg, Germany (15-20 July). We would be glad to discuss any of the ongoing and future projects with the ultrafast community at our tabletop. Hope to see you soon!
Avesta’s facilities will be closed for the New Year break from 30 Dec 2017 till 08 Jan 2018. We will resume all operations on 09 Jan 2018. However, we hope to provide periodic e-mail correspondence during the holidays. We wish you a fruitful and prosperous Year 2018!