A monolithic three-channel LD-PD array with vertically staggered facets for autofocusing reflectivity sensors

A monolithic three-channel LD-PD array with vertically staggered facets is proposed for an autofocusing reflectivity sensor which uses light feedback. The focus-sensing characteristics are investigated using an array with a radiation facet displacement of 12 mu m and an interchannel distance of 130 mu m, fabricated on an 830-nm AlGaAs/GaAs multiple-quantum-well laser substrate with buried-heterostructure stripe geometry waveguides. High focus-sensing accuracy is achieved. A potential application of the array to optical heads for phase change media is discussed.<
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