Measurement of force by means of fiber-optic sensors.

Various principles of measuring force by means of fiber-optic sensors such as fiber to fiber transmission modulation, microbending, elastooptic modification of the state of polarization (induced birefringence) are shortly reviewed. A novel method of measuring force by means of bending a Fiber Fabry-Perot-(FFP-) resonator is described. This interferometric FFP-sensor is easily applicable to AC force measurements, but makes special temperature compensation schemes necessary if DC forces are to be measured. The FFP force sensor can be designed to meet a wide dynamic range at high sensitivity.