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Grating-coupled surface emitting quantum well semiconductor lasers

The design and operation of the grating coupled surface emitting lasers with strained quantum wells for the active and the grating sections are described. Schematic presentation of coupled grating surface emitting (CG-SE) DBR and unstable resonator surface emitting (UR-SE) DBR lasers is shown. A strained quantum well structure was used for both the gain and grating regions. The feedback resonance is obtained using first-order (or second-order) Bragg grating, while surface emission is achieved by chirped or detuned second order gratings. The laser with focusing capability is fabricated by combining first order Bragg grating with chirped circular grating outcoupler.