4-WAVELENGTH DBR LASER ARRAY USING SELECTIVE MOCVD GROWTH

A four-wavelength DBR laser array, fabricated using selective metalorg anic vapor-phase epitaxy (MOCVD) growth, has been developed as a light source for a wavelength division multiplexing (WDM) system. Four diff erent lasing wavelengths were obtained by varying the thickness of the waveguide. This enabled fabrication of lasers having different wavele ngths but gratings with the same pitch. First, the InGaAsP layer grown on an InP substrate which was patterned with stripes of different wid ths by using an SiO2 mask is evaluated. The growth rate of the InGaAsP layer between SiO2 masks could be varied to twice as fast as in a fla t area while maintaining good quality of the crystal. Next, a four-wav elength DBR laser array is fabricated by using selective MOCVD growth and a grating with the same pitch. The lasing wavelength was controlle d at 5-nm intervals over a 15-nm range.