To provide an optical pickup device capable of raising photo-detecting sensitivity of a photo-detector by converting short wavelength light emitted from a light source into long wavelength light, and also performing output control of the light source with high accuracy by improving a utilization efficiency of the converted long wavelength light.
In the optical pickup device 20 which detects a part of the light emitted from the light source 21 by the photo-detector 30 for output monitoring and performs optical output control of the light source 21, a wavelength conversion element 31 for partly converting the incident light of a wavelength λ1 into the light of a wavelength λ2 longer than the wavelength λ1 is prepared on the light receiving surface of the photo-detector 30 for output monitoring. This wavelength conversion element 31 is almost hemispherical, and about the external hemispherical periphery, the remaining part except a window 40 for making the light incident thereto is provided with a light reflection part 43 for reflecting the light.
Takeshi Sugiyama
Minetarou Hirose