Validation of model of external-cavity semiconductor laser and extrapolation from five-element to multielement fiber-coupled high-power laser

The model used to explain the operation of an external cavity containing five discrete antireflection (AR)-coated semiconductor lasers and a spatial filter to assure coherent output from the cavity has been experimentally validated. This model predicts that the external cavity will operate as a coherent source with a multitude of discrete individual lasers and/or monolithic arrays. Control by an external cavity of the series combination of an optical fiber and an AR-coated semiconductor laser has previously been demonstrated. For systems requiring high average-power operation, distributed AR-coated lasers that are fiber-coupled into an external cavity provide a potential alternative to broad-area lasers or monolithic laser arrays with high density of power dissipation which must use thermoelectric or other cooling. An annular input to the external cavity from an array of fibers is proposed for high beam quality