- 标题
- 摘要
- 关键词
- 实验方案
- 产品
-
Time-resolved measurements of two-color laser light emitted from GaAs/AlGaAs-coupled multilayer cavity
摘要： We measured the two-color laser oscillation from a GaAs/AlGaAs-coupled multilayer cavity at 18 °C–42 °C using current injection. We confirmed simultaneous lasing by detecting the sum frequency generation signal generated by the two-color laser light, and performed time-resolved measurement using a streak camera with a spectrometer. From the observed time transient of the spectra at various temperatures, it is clarified that the temperature change of the device, induced by current injection, modulates the effective cavity length. Therefore, the temperature control of the device is a key factor in stable two-color lasing and THz wave generation.
关键词： time-resolved measurements,sum frequency generation,THz wave generation,GaAs/AlGaAs-coupled multilayer cavity,two-color laser
更新于2025-09-19 17:13:59
-
Methyl Made Noncentrosymmetric Stacking: A Promising Organic Single Crystal for Highly Efficient Terahertz-wave Generation
摘要： Regulating secondary bonds in organic compounds is one of the important routes to design practical materials with excellent performances. However, it is still a great challenge to control molecular arrangement and spatial configuration by changing limited substituent groups. Herein, two indolium-based (C19H20NO)+ crystals, centric OHI-CBS and acentric OHI-T were synthesized and grown by evaporation method. An intriguing structural change from centrosymmetric (P21/c) to noncentrosymmetric (Cc) space group was obtained by a simple substitution from chloro- to methyl. Theoretical calculations demonstrate hydrogen bonds and π-π interactions make a dominated contribution to molecular spatial alignment. Meanwhile, OHI-T crystal exhibits prominent nonlinearity about 0.7 times that of the benchmark OH1 crystal, wide band gap (2.47 eV), wide transparency range (504 - 2100 nm), and remarkably efficient output energy among 0.1 - 20 THz region, suggesting it is a potential nonlinear optical media for THz-wave generation. This work realizes the rational crystal structural regulation by simple molecular subsitution and provides a feasible design strategy for other organic optoelectronic functional materials.
关键词： indolium-based crystals,π-π interactions,hydrogen bonds,THz-wave generation,nonlinear optical media
更新于2025-09-19 17:13:59
-
[IEEE 2019 44th International Conference on Infrared, Millimeter, and Terahertz Waves (IRMMW-THz) - Paris, France (2019.9.1-2019.9.6)] 2019 44th International Conference on Infrared, Millimeter, and Terahertz Waves (IRMMW-THz) - Frequency-and-polarization-controllable High-power THz Wave Generation Using Organic Nonlinear Optical Crystal
摘要： Arbitrary control of high-power THz polarization and frequency is studied by the numerical calculation based on the coupled wave approach. THz wave generation using organic crystals via optical rectification provides high conversion efficiency. To overcome the limitation of the generated THz field direction which comes from their optical anisotropy, we propose the synthesis of THz wave generated from two crystals whose optical axis are orthogonal each other. By the calculation, the linearly and circularly polarized THz wave generation by changing the time delay of two pump pulses is demonstrated.
关键词： optical rectification,organic nonlinear optical crystal,polarization control,frequency control,THz wave generation
更新于2025-09-16 10:30:52
-
[IEEE 2019 Conference on Lasers and Electro-Optics Europe & European Quantum Electronics Conference (CLEO/Europe-EQEC) - Munich, Germany (2019.6.23-2019.6.27)] 2019 Conference on Lasers and Electro-Optics Europe & European Quantum Electronics Conference (CLEO/Europe-EQEC) - DSTMS-Based Ultrabroadband Terahertz Time-Domain Spectroscopy
摘要： DSTMS organic electro-optic crystal is a very promising and efficient THz-wave generation material. It allows for both very high THz electric fields generation, exceeding several GV/m using optical rectification of femtosecond laser pulses, as well as the possibility for extremely broad bandwidth extending well beyond 10 THz. However, the usual laboratory THz systems based on these crystals exploit very bulky and expensive fs laser systems, which are not desired for industrial THz imaging and spectroscopy applications. Recently, some compact system employing organic crystals were demonstrated, however they use a conventional photoconductive antenna as a THz-wave detector. Here we present a compact THz time-domain spectroscopy system based on a relatively low-cost and small-size femtosecond fiber lasers operating at 1560 nm. As the THz generation and detection material, we choose the organic crystal DSTMS (4-N,N-dimethylamino-4’-N’-methyl-stilbazolium 2,4,6-trimethylbenzenesulfonate), since it reaches the highest overall efficiency and the flattest spectrum among the presently known state-of-the-art organic crystals. The developed terahertz system is capable of achieving frequencies up to 20 THz with a high dynamic range of more than 60 dB. We use a commercial femtosecond laser with pulse length of 18 fs, 200 mW average power, 40 MHz repetition rate and 1560 nm wavelength as pump beam. We achieve a very large frequency bandwidth reaching 20 THz, profiting from using DSTMS as both THz generator and THz coherent detector material.
关键词： DSTMS,organic crystal,terahertz time-domain spectroscopy,THz-wave generation,femtosecond fiber lasers
更新于2025-09-12 10:27:22