Wide stripe single and dual wavelength mode semiconductor diode lasers

Wide stripe semiconductor lasers have a wide variety of applications in remote sensing, in materials processing applications such as drilling and welding, and as pumps for gas lasers. The emission spectra of simple cost-effective Fabry-Perot (F-P) lasers tends to be very broad, i.e. in the 5-10 nm range at very high power levels, making their use ineffective in some of the above mentioned applications. In order to overcome the problem faced by wide stripe diode lasers with respect to emission wavelength, external gratings such as volume Bragg gratings have been used. These external gratings not only significantly drive up the cost of such integrated systems but also have their drawbacks in that they are very sensitive to mechanical vibrations. This work has focused on the use of an internal grating, a distributed Bragg reflector (DBR) grating that was monolithically inserted into the gain section of a semiconductor laser. The result is a single wavelength mode semiconductor laser capable of delivering high power levels. These lasers were made to have an emission wavelength of around 980 nm. The concept of a wide stripe, single wavelength mode laser eventually led to the creation of a wide stripe, dual wavelength mode laser. These lasers, apart from delivering high power levels, were also made to oscillate on two specific predetermined wavelengths. The laser has two different DBR gratings that were placed next to each other within the gain guided cavity. The wavelengths of interest were determined by controlling the respective pitches of the DBR gratings in accordance with the Bragg condition. The difference frequency between both wavelength modes can be tuned to be in the terahertz (THz) range, leading to interesting THz frequency generation experiments and eventual applications.

Name thesis:degree_name

Ph.D.

Level thesis:degree_level

Dissertation

Discipline thesis:degree_discipline

Electrical & Computer Engr

Grantor

University of Illinois at Urbana-Champaign

Year dc:date

2011

Author dc:creator

• Reddy, Uttam

Contributors dc:contributor

• Coleman, James J.
• Schutt-Ainé, José E.
• Li, Xiuling
• Bryce, Catrina

• Semiconductor Laser
• Distributed Bragg Reflector (DBR) gratings
• Broad Area
• Narrow linewidth

Statement dc:rights

• Copyright 2011 Uttam Reddy

Language dc:language

en

Handle dc:identifier

http://hdl.handle.net/2142/24510

OAI identifier oai:identifier

oai:www.ideals.illinois.edu:2142/24510