Wavelength-graded horizontal cavity laser array with postgrowthadjustment of wavelength

Wavelength-graded emission from a visible red GaInP-AlGaInP laser diode array has been achieved with the contradirectional surface-mode coupling technique. The wavelength control is attained by postgrowth adjustment of the thickness of the surface waveguide. The horizontal cavity lasers show both edge and surface emission (beam divergence 0.12°). The thermal red-shift of the wavelength is 0.028±0.002 nm/K. They show single-mode emission with a typical spectral linewidth of 0.09 nm and a sidemode suppression ratio 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)