We have studied the history of vibration and demonstrate a laser-based noncontact interferometric vibration sensor. The sensor promises the measurement of microdisplacement by using a Fabry–Perot cavity formed between a partially coated gradient-index lens and a movable reflector. Displacement is determined by the detection of interference fringes caused by phase modulation within the cavity. The sensor was tested in conjunction with both multimode and single-mode fiber transmission. Calibration with multimode fiber produced a fringe-contrast function that decreased monotonically with displacement. This calibration allowed at least 30 fringes to be discriminated, giving a displacement resolution of 0.034 μm across a range of 10.2 μm. Dynamic tests demonstrated a working range of at least 3.74 μm at frequencies as high as 2 kHz. Similar tests in which single-mode fiber was used indicated a dynamic working range of at least 4.29 μm.
© 1999 Optical Society of America
(060.2370) Fiber optics and optical communications : Fiber optics sensors
(100.2650) Image processing : Fringe analysis
(120.3180) Instrumentation, measurement, and metrology : Interferometry
(120.7280) Instrumentation, measurement, and metrology : Vibration analysis
(130.6010) Integrated optics : Sensors
Tarun Kumar Gangopadhyay and Philip James Henderson, "Vibration: History and Measurement With an Extrinsic Fabry–Perot Sensor With Solid-State Laser Interferometry," Appl. Opt. 38, 2471-2477 (1999)