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eng Copyright 1996 Smith, Gary Michael Engineering, Electronics and Electrical Physics, Optics Engineering, Materials Science Coleman, James J. Smith, Gary Michael 2011-05-07T11:57:28Z 2011-05-07T11:57:28Z 10000-01-01 1996 Single frequency semiconductor lasers are of interest for communication systems and spectroscopy. In communications, narrow linewidth is desirable to minimize dispersion effects and low cross-talk multiple wavelength channels on a single fiber. For GaAs-based lasers, the interest in narrow linewidth sources comes from the spectroscopy community that desires a light source that can be tuned to very narrow absorption spectra of various materials. For both of these applications, narrow linewidth, wavelength tunable semiconductor lasers are well-suited. This thesis describes the development of a single epitaxial growth ridge waveguide distributed Bragg reflector (RW-DBR) laser. These lasers exhibit low thresholds, fairly high slope efficiencies, and single frequency operation with very narrow linewidth. The fabrication requires only a single epitaxial growth of a standard laser structure and then an anisotropic etch to transfer a grating pattern from the top surface of the laser into the epitaxial layers. The initial RW-DBR lasers fabricated by this method had symmetric cladding layers with a thickness of 1.2 $\mu$m, which required etch depths of over 1 $\mu$m in order to couple adequately to the optical mode. This required a highly anisotropic etch and limited the device design to third-order gratings. However, fairly good device performance was demonstrated with these symmetric cladding RW-DBR lasers. To relax the constraints on the grating etch, an asymmetric cladding separate confinement heterostructure (AC-SCH) laser was developed. The AC-SCH design reduces the thickness of the top cladding layer, which results in shallower depths for the grating etch and allows the fabrication of more efficient second-order DBR gratings. The incorporation of the AC-SCH into the RW-DBR laser reduces the threshold current, increases the efficiency, and decreases the spectral linewidth. Made available in DSpace on 2011-05-07T11:57:28Z (GMT). No. of bitstreams: 2 license.txt: 4922 bytes, checksum: 910b249b4beec47e7ab768910c8f966f (MD5) 9625195.pdf: 2653017 bytes, checksum: e344bc1f6c4d663fffb106ac690dd84f (MD5) Previous issue date: 1996 Item marked as restricted to the 'UIUC Users [automated]' Group (id=2) by Howard Ding (hding2@illinois.edu) on 2011-05-07T14:34:46Z Item is restricted indefinitely. Restriction data tranferred 2014-07-01T11:13:26-05:00 Original Data Group with Access UIUC Users [automated] Release Date: none Reason: ETDs are only available to UIUC Users without author permission ETDs are only available to UIUC Users without author permission U of I Only AAI9625195 (UMI)AAI9625195 http://hdl.handle.net/2142/19117 Single frequency semiconductor lasers text Electrical and Computer Engineering Electrical Engineering University of Illinois at Urbana-Champaign Dissertation Ph.D.