| 摘要 |
PURPOSE:To adjust a transmissive wavelength band simply by using an interference filter as a wavelength selcting optical filter of a photodetecting part, and setting up the interference filter so as to be inclined from incident light. CONSTITUTION:If the interference filter 7' is properly inclined from the incident light, the transmissive wavelength band is changed by regarding the angle theta of inclination is a parameter. Since the property shifting the transmissive band gradually to a short wavelength is recognized by increasing the angle theta of inclination of the interference filter 7', the constitution of a photodetecting part having the optimum transmissive wavelength band width and preventing the incidence of background light by properly inclining the interference filter 7' in accordance with the shift depending upon the variance of the light emitting center wavelength of a light emitting element or the temperature, etc. on the transmission side is obtained. |
