VERTICAL CAVITY SURFACE EMISSION LASER HAVING LATERAL INTEGRATED PHOTODETECTOR

PROBLEM TO BE SOLVED: To adjust a current from a current source automatically by forming a separating region for separating a lateral integrated photodetector, formed adjoining a vertical cavity surface emission laser(VCSEL) on a board from the VCSEL. SOLUTION: A VCSEL30 and lateral integrated photodetectors 40 are formed as approximately-rectangular structures, and the photodetectors 40 are formed in the periphery of or adjoining the VCSEL30. Between the VCSEL30 and the photodetectors 40, a separating region 53 for interrupting or absorbing lateral current scattering or a lateral spontaneously emitted laser beam is arranged. These can be formed by asymmetrical structure, and it becomes possible to distinguish a point at which a change in the laser power is detected by detecting a reflected laser beam and processing information obtained by monitoring the emitted and reflected laser beam of the VCSEL30 using a feedback system by the photodetectors 40, so that it becomes possible to automatically adjust a current from a current source to be used for driving the VCSEL30.