| 摘要 |
PURPOSE:To reduce an irregularity in incident light intensity to a photodetector disposed at the rear of a light emitting element according to the position of the photodetector by disposing the distance of a light emitting position at the end of a semiconductor laser and the outermost layer surface of the electrode nearest to the emitting position to 10mum or shorter. CONSTITUTION:A distance from an active layer 10 to a boundary 13 between crystal electrodes is increased at an electrode outermost layer 11 of the side fusion-bonded to the same heat sink 2, and a distance from a light emitting unit position 101 to the surface 21 of the heat sink 1 is 10mum or longer. The formation of a thick electrode layer by a normal depositing method is not so practical, and a thick gold layer of 3mum or larger is adapted by the plating. In case of h=10mum, the width of the irregularity in the incident light quantity to the photodetector having 200mum of photodetecting diameter is approx. 1.3:1 in calculation, and in case of h=15mum, it becomes approx. 1.1:1 in calculation. Even if the increase in the irregularity due o the displacement from the approximate value occurring in the actual case is considered, the irregularity in the incident light quantity is largely improved as compared with the case of h 5mum.
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