LIGHT DETECTOR

PURPOSE:To obtain the accurate output proportional to the amount of received light when the light is received by a plurality of light guides, by expanding the light received by the light guides to the entire surface of a photoelectric plane of a photoelectric multiplier tube and inputting the light in the tube. CONSTITUTION:The light reflected by a sample is received by a plurality of light guides 4-7, and transmitted to a photoelectric multiplier tube 8. For this purpose, a holder 11 supports the light guides 4-7 so that the end surfaces of the light guides 4-7 are located at the points separated from the central part of the photoelectric plane of the photoelectric multiplier tube 8 by an equal distance R. The distance R is determined in such a way that the light emitted from the light guides 4-7 is expanded to the approximately entire surface of the photoelectric plane of the photoelectric multiplier tube 8.