OPTIMIZING 1550NM INGAASP STRAIN COMPENSATED MQW LASERS CLOSE TO THE MISCIBILITY GAP

Fabry Perot 1550 nm sources are required for a number of high volume s hort haul applications, and an optimised device design is sought which is suitable for wide temperature range operation, Strain compensated multiquantum well lasers with between five and 11 wells were produced using MOCVD with similar to 1% compressive strain in the wells, and si milar to 1% tensile strain in the barriers, Electrical, optical, X-ray and TEM studies were used to determine the material properties, Altho ugh RT-PL measurements indicated good material qualify for all wafers, significant degradation in device properties was observed for larger well numbers. TEM studies are presented which show the degradation to be due to the onset of 'wavy layer' growth, which is also responsible for a broadening of the satellite peaks in the X-ray rocking curves fo r the material, Although wavy layer effects constrain the matrix, high duality devices were produced with low thresholds, high output powers , and wide temperature range operation.