Crystal Growth and Optical, Nonlinear Optical, Thermal and Terahertz Time Domain Spectra of l-Histidine Single Crystal: A Potential Terahertz Material

Abstract

Nonlinear optical (NLO) single crystals have become very useful for second harmonic generation, fiber-optic communications, electro-optic modulation techniques, terahertz (THz) wave generation and detection, and other numerous applications. Researchers exploring crystals need to identify appropriate NLO materials in order to achieve the aforementioned objectives. In the present work, crystals of l-histidine (LH), which is an amino acid, were successfully grown by a slow evaporation technique over a period of 35 days. Powder X-ray diffraction (PXRD) was used to determine the structural information and lattice parameters. The functional groups and vibrational modes present in the compound were confirmed by FT-Raman spectral analysis. The crystals were then subjected to an etching study, which revealed that the crystal is not significantly deformed by solvent action. Optical characteristics were studied under UV–vis spectroscopy and photoluminescence (PL) analyses. It has been found that the crystal has a broad transparency between 250 and 900 nm, which makes it suitable for second harmonic generation (SHG) of lasers in the blue region of the electromagnetic spectrum (EM). The low frequency absorption spectra for LH single crystals in the range of 0.8 to 2.5 THz were analyzed by terahertz time-domain spectroscopy (THz-TDS). The THz spectra of LH show that the THz wave is highly sensitive to the crystal, and the refractive index was also evaluated at different frequencies. The stability to temperature and thermal phase changes of LH were investigated using thermogravimetric analysis (TGA) and differential thermal analysis (DTA). The value of the laser-induced damage threshold was discovered to be 4.65 times greater than the potassium dihydrogen phosphate (KDP) value. The third-order nonlinear behavior of the LH single crystal was investigated using a 10 ns pulsed Nd:YAG laser operating at wavelengths of 1064 and 532 nm. The nonlinear optical parameter α for the LH crystal was determined through Z-scan measurements.

Far IR field generation by mixing of cosh-Gaussian and dark hollow Gaussian laser in encapsulated plasma

“…The desired frequency of THz radiation is realized 2.29 10 Hz. 13 ´The equilibrium plasma density is considered to be 1.5 10 cm . 17 3…”

“…In the context of the development of THz technology, the recent contributions of various research groups have significantly advanced the understanding of the generation of THz waves and their applications. Yadav et al [13] successfully demonstrated the suitability of a sizable crystal of L-Histidine for THz applications, which remarkably exhibits thermal stability up to 275.5 °C, possesses a band gap of 4.4 eV, and exhibits frequency absorption spectra in the range of 0.8-2.5 THz. Zhang et al [14] reported the design of a highly efficient THz detector incorporating a Tamm cavity, which involves an embedded detector chip within a multilayer Si/air Distributed Bragg Reflector (DBR) for significant enhancement of the strength of the THz signal.…”

Broadband terahertz absorption and Q-switching behavior of 5-chloro-2-nitroaniline (5C2NA) crystals

“…Terahertz-Time Domain Spectroscopy (THz-TDS) analysis is performed to access the electronic behavior of the molecules in THz region. Numerous organic materials exhibit promising potential for applications in NLO techniques, such as N-benzyl-2-methyl-4-nitroaniline (BNA), 4-N,Ndimethylamino-4 ′ -N ′ -methyl-stilbazolium tosylate (DAST), and 4-N,N-dimethylamino-4 ′ -N ′ -methyl-stilbazolium 2,4,6trimethylbenzenesulfonate (DSTMS) [19]. These materials are particularly active NLO materials and are frequently employed in techniques like difference frequency generation and optical rectification to generate THz waves.…”