Wavelength-graded horizontal cavity laser array with postgrowth adjustmentof wavelength

Wavelength-graded emission from a visible red GaInP-AIGaInP laser diode arr ay has been achieved with the contradirectional surface-mode coupling techn ique. The wavelength control is attained by postgrowth adjustment of the th ickness of the surface waveguide, The horizontal cavity lasers show both ed ge and surface emission (beam divergence 0.12 degrees). The thermal red-shi ft of the wavelength is 0.028 +/- 0.002 nm/K, They show single-mode emissio n with a typical spectral linewidth of 0.09 nn and a sidemode suppression r atio up to 29 dB, The wavelength spacing between the individual lasers is 0 .76 +/- 0.08 nm yielding a total range across the array of 5.4 nm (from 681 .5 to 686.9 nm).