Generating High-Order Transverse Patterns in Optically Pumped Semiconductor Lasers

• Published in: IEEE journal of selected topics in quantum electronics Vol. 25; no. 6; pp. 1 - 7
• Main Authors: Tuan, Pi-Hui, Hsieh, Yen-Hui, Tu, Chin-Wei, Lee, Chi-Chun, Tsou, Chia-Han, Liang, Hsin-Chih, Huang, Kai-Feng, Chen, Yung-Fu
• Format: Journal Article
• Language: English
• Published: New York IEEE 01.11.2019; The Institute of Electrical and Electronics Engineers, Inc. (IEEE)
• Subjects: Gaussian beams (optics); laser beam characterization; Laser beams; Laser excitation; Laser modes; Nonuniformity; Optical pumping; optical vortices; Pattern generation; Power generation; Pump lasers; Scanning; Semiconductor lasers; Semiconductors; Solid state lasers; Transverse electromagnetic modes; Vertical emitting lasers
• ISSN: 1077-260X; 1558-4542
• DOI: 10.1109/JSTQE.2019.2921380

High-order pattern formation in an optically pumped semiconductor laser (OPSL) under a selective pumping with varying spatial overlap between the pump beam and transverse modes is explored. In contrast to transverse pattern generation by off-axis pumped solid-state lasers where the mode order can be flexibly increased, experimental results reveal that the selective pumping fails to realize high-order mode operation in OPSLs when the pump-to-mode size ratio and pump power are insufficiently large. On the other hand, several high-order patterns belonging to the Hermite-Laguerre-Gaussian (HLG) modes are observed when scanning a large-ratio pump beam to specific positions on the gain chip. These HLG modes are experimentally confirmed to mainly originate from the transverse non-uniformity of present OPSL chip, while their structural features cannot be simply correlated with the pump scanning positions. Nevertheless, it is believed that the first-time observation of pure HLG modes under the large-ratio pumping can offer useful insights into the high-order pattern manipulation in OPSLs.