| 摘要 |
<p>A conventional coherent light source has a large number of components and a complex optical system, and therefore it is difficult to enhance the output of the optical system and downsize and stabilize the optical system. Furthermore, adjustment of optical axis is difficult because the optical axis of generating harmonics has an angle with respect to the optical axis of a basic wave incident light. The inventive coherent light source comprises a light source, a wavelength conversion element for converting a part of a basic wave emitted from the light source into harmonics, and a wavelength selection filter exhibiting narrow band transmission characteristics for the part of the basic wave not converted into harmonics and exhibiting transmission characteristics for the harmonics. The inventive coherent light source is characterized in that the part of the basic wave emitted from the wavelength conversion element and not converted into harmonics is fed back to the light source by the wavelength selection filter, and the harmonics pass through the wavelength selection filter and exit outward. Consequently, a stabilized, high-output short wavelength light source exhibiting excellent mass productivity can be realized.</p> |
