High performance mid-infrared electrically pumped semiconductor lasers

• Main Author: Lyu, Xiaomeng
• Other Authors: Wang Qijie
• Format: Thesis-Master by Coursework
• Language: English
• Published: Nanyang Technological University 2024
• Subjects: Engineering
• Online Access: https://hdl.handle.net/10356/173514
• Institution: Nanyang Technological University

Quantum Cascade Lasers represent a groundbreaking development in the field of optoelectronics, offering unparalleled advantages in terms of wavelength coverage, tunability, and power efficiency. This dissertation explores the development history of QCL technology, aiming to unravel the underlying principles, engineering challenges, and the wide spectrum of applications that benefit from these innovative devices. In terms of background analysis, the dissertation commences with an in-depth review of the fundamental principles governing QCL operation, elucidating the quantum mechanics and band structure engineering that distinguish QCLs from traditional semiconductor lasers. Special emphasis is placed on the design considerations and material choices influencing performance characteristics. Furthermore, it investigates the expanding landscape of applications leveraging QCL technology. From high-resolution spectroscopy to trace gas sensing and medical diagnostics, QCLs have demonstrated their versatility in diverse fields. In preparation for the experiment, mainly for the introduction of experimental equipment and device manufacturing methods, introduced the measuring equipment and testing methods, QCL manufacturing process and experimental platform construction. At the same time, in order to improve the quality of QCL emission spectrum, several methods to improve the quality of laser emission are introduced, the structure of QCL flat laser, the development history and application methods of F-P cavity, different platform design methods and spectral analysis are introduced. In the experimental part, through the use of some of the above experimental equipment and testing methods, mainly to complete the analysis of two parts. First, the spectrum of QCL and the characteristic curve of LIV in a certain band were observed. This paper selected the range of ~7.3µm for observation, so as to obtain a general rule. The main content of the second part is to design a mid-infrared laser device with a wavelength of ~4.8µm. On the basis of QCL, different multi-ring structures are used to improve the quality of its emitted light waves, and find the best solution is found by comparison.