| 摘要 |
PURPOSE:To obtain superior wavelength selecting performance by forming a gap which slants slightly in the center of a light convergent lens and forming on the gap, a vapor-deposited film for increasing reflectivity to wavelength in use, and thus forming the light convergent lens and an etalon in one body. CONSTITUTION:At the reflection end 3 of the light convergent lens 1, the vapor- deposited film with high reflectivity is formed and in the center, the parallel gap 5 which has a small slanting angle theta and an interval (d) of size corresponding to the wavelength to be selected is provided. This gap 5 is polished and the vapor- deposited film with high reflectivity to the wavelength in use is formed to obtain functions of the etalon. Because of the slanting angle theta, reflected light with large band width is guided out of a resonator effectively to obtain a narrow band. Consequently, the light convergent lens and etalon are formed in one body and even when the sectional area of an incident beam is small and parallelism is inferior, superior wavelength selecting performance is obtained. |
