Type
Text
Type
Dissertation
Advisor
Shterengas, Leon | Dhadwal, Harbans | Gouzman, Mikhail | Hwang, David.
Date
2015-08-01
Keywords
cascade, Diode, GaSb, infrared, Laser, type-I | Engineering
Department
Department of Electrical Engineering.
Language
en_US
Source
This work is sponsored by the Stony Brook University Graduate School in compliance with the requirements for completion of degree.
Identifier
http://hdl.handle.net/11401/77473
Publisher
The Graduate School, Stony Brook University: Stony Brook, NY.
Format
application/pdf
Abstract
Mid infrared semiconductor diode lasers have broad range of applications, including light detection and ranging, infrared countermeasures, medical treatment and spectroscopy. Compact and efficient devices operating in continuous-wave (CW) regime at room temperature (RT) are preferred for those applications. This work is focusing on the development of GaSb-based type-I quantum wells (QWs) diode lasers in the spectral range of 2.2 - 3.4 µm, with high output power and Diffraction-Limited beam. The novel design of cascade type-I QWs diode lasers was proposed. The interband tunneling through the " leaky" window in band alignment at GaSb/InAs heterointerface was used to realize cascade pumping of type-I GaSb QWs in the device active region. The GaSb/InAs tunnel junction required only moderate n-doping on InAs side and, thus, did not generate excessive absorption losses despite being located near the transfer mode peak. The two-stage cascade design provides twofold increase of the device slope efficiency as compared to that of single stage diode lasers. Corresponding high CW power RT operated 2.4 - 3.3 µm two-stage cascade diode lasers were fabricated. The cascade structure was further optimized to improve the QW optical confinement factor, and the threshold current density was reduced. The two- and three-stage cascade diode lasers demonstrated CW output power of 650 mW and 960 mW at 3 µm in RT, respectively. Diffraction-Limited and distributed feedback diode lasers with narrow ridge waveguide were designed and fabricated. Various etching techniques (wet etching, Cl2-free and Cl2-based dry etching) were developed to improve the etching profile and lasers performance. Diffraction-Limited cascade diode lasers demonstrated CW output power of 100 mW at 3 µm, and 40 mW at 3.15 µm in RT, respectively. Distributed feedback 3.27 μ m diode lasers demonstrated CW output power of 15 mW at RT. | Mid infrared semiconductor diode lasers have broad range of applications, including light detection and ranging, infrared countermeasures, medical treatment and spectroscopy. Compact and efficient devices operating in continuous-wave (CW) regime at room temperature (RT) are preferred for those applications. This work is focusing on the development of GaSb-based type-I quantum wells (QWs) diode lasers in the spectral range of 2.2 - 3.4 µm, with high output power and Diffraction-Limited beam. The novel design of cascade type-I QWs diode lasers was proposed. The interband tunneling through the " leaky" window in band alignment at GaSb/InAs heterointerface was used to realize cascade pumping of type-I GaSb QWs in the device active region. The GaSb/InAs tunnel junction required only moderate n-doping on InAs side and, thus, did not generate excessive absorption losses despite being located near the transfer mode peak. The two-stage cascade design provides twofold increase of the device slope efficiency as compared to that of single stage diode lasers. Corresponding high CW power RT operated 2.4 - 3.3 µm two-stage cascade diode lasers were fabricated. The cascade structure was further optimized to improve the QW optical confinement factor, and the threshold current density was reduced. The two- and three-stage cascade diode lasers demonstrated CW output power of 650 mW and 960 mW at 3 µm in RT, respectively. Diffraction-Limited and distributed feedback diode lasers with narrow ridge waveguide were designed and fabricated. Various etching techniques (wet etching, Cl2-free and Cl2-based dry etching) were developed to improve the etching profile and lasers performance. Diffraction-Limited cascade diode lasers demonstrated CW output power of 100 mW at 3 µm, and 40 mW at 3.15 µm in RT, respectively. Distributed feedback 3.27 μ m diode lasers demonstrated CW output power of 15 mW at RT. | 131 pages
Recommended Citation
Liang, Rui, "Mid-infrared GaSb-based Type-I Quantum Wells Diode Lasers Utilizing Cascade Pumping Scheme" (2015). Stony Brook Theses and Dissertations Collection, 2006-2020 (closed to submissions). 3285.
https://commons.library.stonybrook.edu/stony-brook-theses-and-dissertations-collection/3285