Shanghai Institute Of Optics And Precision Machinery (SIPM) Makes Progress in Research On Strong-field Terahertz Light Sources Based On Organic Crystals

Recently, the State Key Laboratory of Intense-Field Laser Physics (SGLIPM) of Shanghai Institute of Optics and Precision Machinery (SIPM), Chinese Academy of Sciences (CAS), has made progress in the research of intense-field terahertz light sources based on organic crystals. The related research results were published in Optics Express under the title Generation and characterization of intense terahertz pulses from DSTMS crystal.
Terahertz waves are valuable in basic scientific research as well as in information and other applications due to their unique frequency and time characteristics. When the terahertz field strength reaches the order of MV/cm, ultrafast modulation of material properties can be realized, including the modulation of fundamental properties such as electrons, phonons, spins, etc., as well as inducing phase transitions in materials. For a long time, the lack of strong-field terahertz wave generation technology is the main factor limiting its wide application. With the development of laser technology, the optical rectification effect in ultrashort-pulse laser-driven crystals provides a reliable solution for the generation of strong-field terahertz waves.
Based on the new generation of integrated experimental device for ultra-intense ultrashort pulse laser of Shanghai Institute of Optics and Mechanics (SIOME), the work uses high-energy infrared laser to drive the optical rectification effect in organic crystal DSTMS, and obtains strong-field terahertz wave with single-pulse energy of 175 μJ and peak field strength of 17 MV/cm by optimizing the phase-matching conditions, with the energy conversion efficiency of 2%, and the frequency spectrum of 0.1-4.5 THz. The researchers used electro-optical sampling, spectral analysis and other means to systematically analyze the characteristics of terahertz waves in the time domain, frequency domain, pump power density dependence. This work promotes the research of strong-field light sources in the terahertz band and provides an excellent driving light source for strong-field terahertz physical property modulation.
This work was supported by the National Natural Science Foundation of China (NSFC), the Instrumentation Development Program of the Chinese Academy of Sciences (CAS), the Talent Introduction Program of CAS, and the Stable Support Program for Young Teams in Basic Research of CAS.

Generation and characterization of strong-field terahertz waves. (a) terahertz time-domain waveform; (b) terahertz spectrum; (c) dependence of terahertz energy and conversion efficiency on pump power density.