Abstract: A fiber squeezer includes a frame that applies a preload to an optical fiber to permit variation of the birefringence thereof by either increasing or decreasing the preload. The optical fiber and a piezoelectric transducer are retained in the frame, and an appropriate voltage source is connected to the piezoelectric transducer to control the force on the fiber, which controls the refractive indices of the fiber by means of the photoelastic effect. The frame may include a pair of generally L-shaped legs fastened together to enclose the piezoelectric transducer and the fiber. The relative positions of the legs are adjustable during assembly of the frame to permit application of the preload to the fiber and transducer fiber squeezer. The frame may also include a generally U-shaped member having a pair of outwardly extending legs with an end plate mounted therebetween. The transducer and the fiber are held between the end plate and the lower portion of the U-shaped member.