摘要 |
<p>A chirped grating surface emitting distributed feedback semiconductor laser device (10) includes a P-side ohmic contact (28) and an N-side ohmic contact (36). A potential difference is applied across these contacts to create an electric field that induces a stimulated emission of coherent photon radiation. The coherent photon radiation produced by the stimulated emission process is incident upon a linearly varying, second order chirped grating surface (29). An output beam, directed normal to a chemically etched output window (38), is produced by a first order diffraction of photon radiation from the chirped grating surface (29). The output beam has a non-uniform longitudinal mode near-field output intensity profile and an non-abrupt longitudinal mode near-field phase, both due to a reduced destructive interference interaction in a second order diffraction of photon radiation along the grating surface (29). The output beam also has a desired single lobed longitudinal mode far-field output intensity profile. Moreover, the device achieves a 20% power efficiency due to the reduced destructive interference in the second order diffraction. <IMAGE></p> |