Abstract: A system and method for measurement of the polarization of fluorescence. A laser source provides a collimated linearly polarized beam of high intensity and small cross-section. A relatively small number of optical components are employed to minimize spurious fluorescence and spurious polarization which usually occurs from most optical materials. A photodetector provides an electrical signal in response to and representative of fluorescence polarization and is processed to directly produce first and second signals representing the difference and sum components of the polarization equation, the ratio of these components being directly provided without need for division computation.

Abstract: Apparatus usable as a fluorometer for measuring the concentration of fluorescent material in a specimen employs a flashing lamp to illuminate the specimen with excitation radiation. The intensity of the fluorescence emitted by the specimen is therefore modulated at the flash rate. That modulated fluorescence is converted by a photodetector to an electrical signal. The electrical signal is amplified and is passed through a phase sensitive detector to an integrator. The phase sensitive detector is regulated to operate at a rate related to the flash rate whereby an appropriately rectified signal is fed to the integrator. When the specimen has been subjected to a selected amount of excitation radiation, a signal is generated which marks the end of the integration interval. The accumulated signal in the integrator is then measured to obtain a measurement of the quantity of fluorescent material in the specimen.