7.3μm slot quantum cascade laser

• Main Author: Ding, Zelong
• Other Authors: Wang Qijie
• Format: Thesis-Master by Coursework
• Language: English
• Published: Nanyang Technological University 2022
• Subjects: Engineering::Electrical and electronic engineering::Optics, optoelectronics, photonics
• Online Access: https://hdl.handle.net/10356/158960
• Institution: Nanyang Technological University

The market for the mid-infrared lasers is growing day by day due to the two significant atomic windows are exactly lying in the mid-infrared range. Various laser sources are developed and researched in order to achieve tunable lasing at the mid-infrared. Among them, QCLs become a hotspot for researchers in recent years due to their unique merits of small size, high efficiency, low power consumption, high quantum efficiency and high output power. In this thesis, we first compare different kinds of mid-infrared lasers. And then we give a literature review of the development of quantum cascade lasers. The structure design and tunable mechanism of the research of quantum cascade lasers are introduced. The novel tunable method of slot quantum cascade laser has the characteristics of none mechanical device controlling and easy fabrication process. So we used this method to conduct both simulation and experiment research. During simulation, we constructed a single slot structure to study the influence of the depth of the slot to the device. Results suggest we use 2.8µm depth to fabricate the slots. During experiment, we measured the spectrum of the slot quantum cascade laser. We got a high tuning range with a side mode suppression ratio of 15dB for the pulsed single mode laser, which shows great potential for the practical application for gas detection.