Patent ID: 8885165

Claim:
A device for detecting fluorescence by receiving fluorescence emitted by n (n is an integer of 2 or more) kinds of measurement objects irradiated with laser light and processing fluorescent signals of the received fluorescence, the device comprising: a light source unit operable to modulate, at two or more different frequencies, intensities of laser beams L k (k is an integer of 1 to n) of different wavelengths prepared so as to correspond to measurement objects k so that optical absorption characteristics of each of the measurement objects are different from those of other one or more kinds of the measurement objects, and operable to output these laser beams L k as one irradiation light to irradiate the n kinds of measurement objects with the irradiation light; a light-receiving unit that includes two or more light-receiving elements operable to receive fluorescence emitted by the n kinds of measurement objects irradiated with the irradiation light within wavelength bands FL k (k is an integer of 1 to n) set so as to correspond to the measurement objects k (k is an integer of 1 to n) so that fluorescence intensity of fluorescence emitted by each of the measurement objects is different from that or those of fluorescence emitted by other one or more kinds of the measurement objects, and operable to output fluorescent signals corresponding to the wavelength bands FL k ; a first processing unit operable to perform frequency-down conversion by mixing each of the outputted fluorescent signals with a modulation signal for modulating at a least one of the intensities of the laser beams L k corresponding to the wavelength bands FL k (k is an integer of 1 to n) as a first reference signal to produce fluorescence data containing a phase delay and an intensity amplitude of each of the fluorescent signals; and a second processing unit operable to correct the produced fluorescence data and determine a phase delay of each of the fluorescent signals using the corrected fluorescence data, and to calculate a fluorescence relaxation time using the phase delay.