US Patent 11280669 Pulsed laser interferometer and measuring vibrational amplitude and vibrational phase

A pulsed laser interferometer includes: a pulsed laser; a vibration controller that produces a vibration control signal that controls a vibrational frequency and vibrational amplitude of a structural member; an interferometer controller; a pathlength control stage that changes an optical pathlength for laser pulses; a pathlength reflector that moves in concert with the pathlength control stage to change the optical pathlength of propagation for the laser pulses; a light pulse detector that produces a light pulse detector signal; an interference light detector that produces an interference frequency signal; a signal mixer that produces a reference frequency signal; and a phase-sensitive detector that produces a vibrational amplitude signal and a vibrational phase signal from the interference frequency signal referenced to the reference frequency signal.