Patent ID: 8654316

Claim:
A target system, comprising: a light source configured to generate a light beam, wherein an intensity of the light beam is modulated at a modulation frequency; front-end optics configured to direct the light beam to a target; an optical filter configured to receive return light from the target, and to separate out elastic light scatter and fluorescent light in the return light, the elastic light scatter in the return light having a different phase than the light beam; a first photodetector configured to receive the elastic light scatter from the optical filter, and to generate an elastic scatter detection signal based on the received elastic light scatter; a second photodetector configured to receive the fluorescent light from the optical filter, and to generate a fluorescent detection signal based on the received fluorescent light; and a detection and computation subsystem configured to compute a phase difference between the elastic scatter and fluorescent detection signals, and to determine a fluorescence lifetime based on the phase difference.