An array of monolithically integrated composite-cavity lasers which has been fabricated on the basis of the chemical etching technique is reported. Each composite-cavity laser consists of a laser and an external reflector, and the reflector is used also as a photodetector. The array is designed so that each laser can be operated independently of the other for parallel processing of optical data with high stability operation and independent monitoring capability. Experimental devices have been successfully fabricated.

Two strip-waveguides, with and without a function of light intensity modulation, have been monolithically integrated with an embedded stripe DH laser. The strip-waveguides are constructed with guide films of high resistivity GaAs0.9 P0.1 and surroundings of slightly lower refractive index GaAs0.85 P0.15. The intensity of spontaneous light output from the stripe Ga0.97 Al0.03 As laser can be modulated by a voltage applied to the waveguide-modulator through an isolated electrode. It is seen that the maximum modulation occurs at a wavelength shorter than the peak wavelength of emission spectrum as a result of the Franz-Keldysh effect.