| 摘要 |
<p>A double-wavelength light source unit capable of a stable signal detection, comprising a double-wavelength light source, a light detector, and a double-wavelength-use diffraction element, wherein the double-wavelength-use diffraction element comprises a diffraction lattice that transmits a light with lambda1 and diffracts a light with lambda2 out of lights with wavelengths lambda1 and lambda2 (lambda1 lambda2) emitted from two semiconductor lasers serving as the double-wavelength light source, a diffraction lattice that transmits a light with lambda 2 and diffracts a light with lambda1, a diffraction lattice that consists of a lattice-forming lattice material and a filling material and transmits a light with lambda1 with the refractive indexes of the both materials being identical and diffracts a light with lambda2 with the refractive indexes being different, and a diffraction lattice that transmits a light with lambda1 and has a first polarizing surface, and diffracts a light with lambda1 on a polarizing surface orthogonal to the former polarizing surface.</p> |
