US Patent 8166825 Method and apparatus for noise reduction in ultrasound detection

Method and apparatus for noise reduction in ultrasound detection with the steps of: an optical interferometer having a reference arm and a signal arm that includes a polarization-maintaining probing fiber having a reflective coating at a distal end, a way to couple the probing fiber to ultrasound, a way to generate two output beams from the interferometer, a device to modulate the polarization state of the light in the probing fiber, and a detection mechanism responsive to the ultrasonic signals at the distal tip of the probing fiber.