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Design, growth, and characterization of vertical cavity surface emitting lasers

Citation

O'Brien, John David (1996) Design, growth, and characterization of vertical cavity surface emitting lasers. Dissertation (Ph.D.), California Institute of Technology. http://resolver.caltech.edu/CaltechETD:etd-05252005-084438

Abstract

Vertical cavity surface emitting laser design, growth, and characterization is discussed. Theoretical models for gain in semiconductors as well as for the threshold gain in vertical cavity lasers is presented. The distributed Bragg mirrors used in these lasers are treated theoretically using the coupled-mode approach and with a matrix method that is generalized to include gain and loss. The growth by molecular beam epitaxy of these structures is also discussed including steps taken to obtain precise, reproducible growth rates. Specific problems and tradeoffs encountered in the growth include greater oxygen incorporation at the lower substrate temperatures needed to ensure precise thickness control. Beryllium diffusion is also discussed and SIMS measurements are presented. Two types of vertical cavity lasers are demonstrated. The first is a hybrid semiconductor/dielectric structure. In this design, the n-doped mirror and the optical cavity are epitaxially grown semiconductors and the top mirror is a SiO2/Si3/N4 distributed Bragg reflector added to the structure by reactive sputter deposition. These lasers have InGaAs quantum wells and are top-emitting near 980 nm. This design has the advantage of removing the top mirrors from the current path which reduces the series resistance. Threshold voltages of 1.8-1.9 V were obtained from 18 µm diameter lasers. In addition, the hybrid structure allows characterization before the deposition of the top mirror. Measurements of the carrier distribution and the temperature of the devices operating without the top mirrors are presented. A minimum lasers threshold current of 2.5 mA was obtained from a 6 µm diameter laser, and a maximum peak power of 1.67 mW was obtained from a 12 µm diameter laser. The lasers exhibit strongly index-guided transverse modes and are multi-moded above threshold.

Item Type:Thesis (Dissertation (Ph.D.))
Subject Keywords:Applied Physics
Degree Grantor:California Institute of Technology
Division:Engineering and Applied Science
Major Option:Applied Physics
Thesis Availability:Restricted to Caltech community only
Research Advisor(s):
  • Yariv, Amnon (advisor)
  • Scherer, Axel (co-advisor)
Thesis Committee:
  • Unknown, Unknown
Defense Date:28 May 1996
Record Number:CaltechETD:etd-05252005-084438
Persistent URL:http://resolver.caltech.edu/CaltechETD:etd-05252005-084438
Default Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:2049
Collection:CaltechTHESIS
Deposited By: Imported from ETD-db
Deposited On:26 May 2005
Last Modified:26 Dec 2012 02:46

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