Premium
Some Effects of Material Inhomogeneities on the Near‐Field Pattern of GaAs Diode Lasers
Author(s) -
Hatz J.
Publication year - 1968
Publication title -
physica status solidi (b)
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.51
H-Index - 109
eISSN - 1521-3951
pISSN - 0370-1972
DOI - 10.1002/pssb.19680280125
Subject(s) - diode , dislocation , materials science , laser , optoelectronics , crystal (programming language) , doping , optics , absorption (acoustics) , attenuation length , physics , computer science , composite material , programming language
Studies are made of the near‐field patterns of diode lasers fabricated from slices of Czochralski‐grown GaAs crystals with dislocation densities between 10 5 cm −2 and zero per slice. Four of the crystals were Te‐doped, the fifth Si‐doped, to 2 × 10 18 atoms cm −3 . Comparison of the crystal qualities with the near‐fields shows that filamentary emission is not an intrinsic property of diode lasers. With decreasing dislocation density the near‐fields become more homogenous. Diodes made from dislocation‐free material, having in addition almost perfect mirrors, emit uniformly over nearly the whole width of the diode at 1.5 times threshold current. The emission from diodes having a high dislocation density (higher than 10 4 cm −2 ) in the active region was strongly filamentary and in some cases the intensity difference between both ends of a filament was as high as 25%. This difference has been accounted for by a simple model of the cavity, which allows for variations of absorption and gain along the optical path.