OPTICAL SEMICONDUCTOR DEVICE, ITS MANUFACTURING METHOD, AND OPTICAL RECORDING DEVICE

PROBLEM TO BE SOLVED: To provide an optical semiconductor device that can avoid the loss of forwardly emitted light beams from a light emitting element and can simplify the production process. SOLUTION: The optical semiconductor device is provided with silicon substrates 30 and 40, which are arranged so that their surfaces are made opposite to each other, and a laser diode 45 which is located on the substrate 40 and emits forwardly emitted light beams L1 to the tip part sides of the substrates 30 and 40. A micromirror is provided on the substrate 40 to reflect external reflected light beams L3, which are made incident from the tip sides, on the substrate 30 side. Moreover, a signal detecting photodiode is provided on the substrate 30 to receive the beams L3 which are reflected by the micromirror.