Author(s): Li, YY (Li, Yuan-Yuan); Zhao, FY (Zhao, Fang-Yuan); Ma, Y (Ma, Yu); Li, WJ (Li, Wei-Jiang); Liu, JQ (Liu, Jun-Qi); Liu, FQ (Liu, Feng-Qi); Luo, JW (Luo, Jun-Wei); Zhang, JCA (Zhang, Jin-Chuan); Zhai, SQ (Zhai, Shen-Qiang); Zhuo, N (Zhuo, Ning); Wang, LJ (Wang, Li-Jun); Liu, SM (Liu, Shu-Man)

Source: OPTICS AND LASER TECHNOLOGY Volume: 143 Article Number: 107346 DOI: 10.1016/j.optlastec.2021.107346 Published: NOV 2021

Abstract: A lens-coupled terahertz (THz) quantum cascade laser (QCL) array with multiple spatially-separated beams is presented. The beam divergence and focusing efficiency after lens are both investigated by simulations and experiments. By integrating an appropriate hyper-hemispherical silicon lens with a well-designed six-element distributed feedback (DFB) QCL array inside the cryostat window, excellent emission characteristics of small divergence angles from 4.1 degrees x3.5 degrees to 7.2 degrees x5.8 degrees and multi-wavelength spectra are realized at 77 K. The deflection angle between adjacent beams is - 10 degrees. The output intensity after lens is 113 to 25 times that of original beams with a focusing efficiency ranging from - 58% to - 37% for lasers at different positions. This method provides a simple solution to form a multi-beam THz source with high intensity and low far-field divergence.

Accession Number: WOS:000684999700001

ISSN: 0030-3992

eISSN: 1879-2545

Full Text: https://www.sciencedirect.com/science/article/pii/S0030399221004345?via%3Dihub