Patent ID: 8642976

Claim:
A device for detecting fluorescence by processing a fluorescent signal obtained by receiving fluorescence emitted by a measurement object which is irradiated with laser light, the device comprising: a light source unit operable to emit laser light with which a measurement object is irradiated while modulating an intensity of the laser light; a light-receiving unit operable to output a fluorescent signal of fluorescence emitted by the measurement object irradiated with the laser light; a light source control unit operable to generate a modulation signal including DC component for modulating the intensity of the laser light emitted from the light source unit; a processing unit operable to calculate, from the fluorescent signal output by the light-receiving unit, a phase delay of the fluorescence emitted by the measurement object with respect to the modulation signal and calculates a fluorescence relaxation time of the fluorescence of the measurement object using the phase delay; and a signal control unit operable to control a frequency of the modulation signal so that a value of the phase delay comes close to a preset value, and operable to adjust an intensity level of the DC component so that an intensity of the fluorescent signal is adjusted to a predetermined level.