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Copyright 2011 Uttam Reddy Semiconductor Laser Coleman, James J. Coleman, James J. Schutt-Ainé, José E. Li, Xiuling Bryce, Catrina Reddy, Uttam 2011-05-25T14:22:27Z 2011-05-25T14:22:27Z 2013-05-26T10:00:21Z 2011-05-25T14:22:27Z 2011-05 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. Item withdrawn by Mark Zulauf (zulauf@illinois.edu) on 2011-04-14T14:43:38Z Item was in collections: University of Illinois Theses & Dissertations (ID: 1) No. of bitstreams: 1 Reddy_Uttam.pdf: 4963705 bytes, checksum: 18201e890ecd67d04faf745fe6f801c1 (MD5) Made available in DSpace on 2011-05-25T14:22:27Z (GMT). No. of bitstreams: 2 Reddy_Uttam.pdf: 4963705 bytes, checksum: 18201e890ecd67d04faf745fe6f801c1 (MD5) license.txt: 4060 bytes, checksum: daa1d3ad5847c302303d98bce8442736 (MD5) Item marked as restricted to the 'Administrator' Group (id=1) by William Ingram (wingram2@illinois.edu) on 2011-05-25T14:30:10Z Item is restricted until 2013-05-25T14:29:35Z Item reinstated by Sarah Shreeves (sshreeve@illinois.edu) on 2013-05-26T10:00:20Z Item was in collections: University of Illinois Dissertations and Theses (ID: 204) Dissertations and Theses - Electrical and Computer Engineering (ID: 446) No. of bitstreams: 3 Reddy_Uttam.pdf: 4963705 bytes, checksum: 18201e890ecd67d04faf745fe6f801c1 (MD5) license.txt: 4060 bytes, checksum: daa1d3ad5847c302303d98bce8442736 (MD5) Reddy_Uttam.pdf.txt: 141164 bytes, checksum: 711af126161f66ad6de3c2338df6d92e (MD5) Item released from any restrictions by Sarah Shreeves (sshreeve@illinois.edu) on 2013-05-26T10:00:21Z http://hdl.handle.net/2142/24510 en Distributed Bragg Reflector (DBR) gratings Broad Area Narrow linewidth Wide stripe single and dual wavelength mode semiconductor diode lasers Electrical & Computer Eng 1933 Electrical & Computer Engr 1200 University of Illinois at Urbana-Champaign Dissertation Ph.D. PHD:Electr & Computer Eng-UIUC 10KS1200PHD