An optoelectronic device that provides an excellent reproduction signal and a stable servo control while preventing deterioration of S/N ratio caused by stray light. The optoelectronic device has a semiconductor laser (101) that emits light beams on an information-recording medium (105), a hologram optical element (102) having a diffraction grating region (108) and located between the semiconductor laser (101) and the information-recording medium (105), and a photodetector (106) for receiving light that is diffracted at the diffraction grating region (108) of the hologram optical element (102), among returning light beams from the information-recording medium (105), and the optoelectronic device has also a diffraction grating region (107) in the vicinity of the diffraction grating region (108) of the hologram optical element (102) so as to prevent stray light other than diffracted light from the diffraction grating region (108) from entering the photodetector (106).