A novel noninvasive acousto-optic device for polarization coupling and frequency shifting in optical fiber based on bulk-shear acoustic waves is reported. By use of a coupled-mode theory, an expression is obtained to predict the amplitude coupling efficiency. An elliptical-core-fiber polarization modulator is demonstrated at a center acoustic frequency of 75 MHz. An amplitude coupling efficiency of 14.3% and a 3-dB bandwidth of 3.6 MHz were observed, comparing well with the predicted results and also comparing favorably with similar devices based on longitudinal strain waves.
© 1993 Optical Society of America
John F. Sevic and David B. Patterson, "Noninvasive polarization eigenmode coupling in elliptical-core optical fiber based on bulk-shear acoustic waves," Opt. Lett. 18, 2008-2010 (1993)