Accession Number : ADA195974

Title :   Tolerances for Phase Locking of Semiconductor Laser Arrays.

Descriptive Note : Technical rept.,

Corporate Author : AEROSPACE CORP EL SEGUNDO CA ELECTRONICS RESEARCH LAB

Personal Author(s) : Garmire, Elsa M

PDF Url : ADA195974

Report Date : 18 Apr 1988

Pagination or Media Count : 25

Abstract : The fabrication and operating conditions for semiconductor laser arrays to be phase-locked are described. The analysis is based on a linear theory of the locking of coupled oscillators. Results show that the refractive index of adjacent lasers must be the same to approx. 0.0001. This puts close tolerances on fabrication if phase-locking is to be maintained. The average aluminum concentration in adjacent stripes must be the same to within approx. 0.0001, while the average epilayer thickness must be the same to within 0.2%, or a tolerance of 3 a on the active layer. Changes in refractive index due to free carrier injection provide an additional tolerance condition, which translates to a requirement that the stripe width and contact resistance be uniform to within a few percent. In addition, because thermal profiles may be detrimental, careful heat-sinking is required. These fabricational tolerances support the fact that high quality epilayers such as grown by molecular-beam epitaxy (MBE) and metal-organic chemical vapor deposition (MOCVD) are usually required for phase-locked laser arrays, and that photoresist processing and bonding must be done carefully. (RH)

Descriptors :   *ARRAYS, *LASERS, *PHASE LOCKED SYSTEMS, ALUMINUM, CHEMICAL REACTIONS, CONCENTRATION(COMPOSITION), EPITAXIAL GROWTH, FABRICATION, INJECTION, LAYERS, LINEARITY, MOLECULAR BEAMS, ORGANOMETALLIC COMPOUNDS, PHOTORESISTORS, PROCESSING, PROFILES, REFRACTIVE INDEX, SEMICONDUCTOR DEVICES, SEMICONDUCTOR LASERS, STRIPES, THEORY, THERMAL PROPERTIES, THICKNESS, TOLERANCE, TOLERANCES(MECHANICS), VAPOR DEPOSITION, WIDTH

Subject Categories : Lasers and Masers

Distribution Statement : APPROVED FOR PUBLIC RELEASE