| 摘要 |
PURPOSE:To enable to oscillate in single wavelength a semiconductor laser by employing a multimode oscillator, selecting the light of the specific wavelength from the emitted lights via a diffraction grating and feeding it back to the laser. CONSTITUTION:The luminous flux emitted from one end surface 4 of a semiconductor laser 1 is reflected and diffracted at a holographic diffraction grating 21, the primarily diffracted light 8 becomes parallel beam, is reflected on a reflecting mirror 22, is again reflected on the holographic diffraction grating 21, is focused on the laser 1, and is fed back. When the laser 1 is oscillated in multimode, the light diffracted via the grating 21 is incident at the different angles according to the wavelengths to the mirror 22. Accordingly, the mirror 22 is regulated so that the light of the desired wavelength is incident to vertical direction. The elements such as the laser element, holographic diffracting grating, reflecting mirror are determined at the relative positions in one package, thereby obtaining the semiconductor laser which is small sized, and can be extremely readily handled provided with stable oscillation wavelength. |
