Birefringence modulation in fiber-optic phase modulators

Subharmonics and chaos generation in all-fiber phase modulator: experimental and theoretical analyses with simulation

We report the results of experimental observation and theoretical analysis of the generation of subharmonic and chaotic signals in a harmonically driven all-fiber phase modulator (PM). When a PM constructed with optical fiber wrapped around a piezoelectric cylinder is driven at high amplitude, we identified that the fiber itself moves with subharmonic frequencies while the piezoelectric cylinder maintains harmonic motion. A theoretical model is presented that is a modification of the model for a bouncing ball on an oscillating table. Some key physical parameters for the model are identified. Potential origins for the discrepancy between the experimental and theoretical analyses are discussed. Ways to suppress the nonlinear effect are also discussed.

Low-frequency and high-frequency all-fiber modulators based on birefringence modulation

In-line optical modulators with low insertion losses and high maximum optical powers are required for Q switching and cavity dumping of fiber lasers as well as for nonlinear optical-fiber experiments. We report the design of polarimetric all-fiber modulators based on optical-fiber birefringence modulation combined with an all-fiber polarizer. Birefringence modulation involves a piezoelectric ceramic tube. This simple technique permits efficient low-frequency and high-frequency harmonic modulation, up to the megahertz range, as well as modulation of pulses shorter than 1 micros.

Analysis of polarization properties of a mode-locked fiber laser gyroscope

We investigated the polarization characteristics of a mode-locked fiber laser gyroscope (MLPLG) formed with a Nd-doped fiber as an optical gain medium and a Sagnac loop mirror. The output pulse patterns and the polarization states were found to be determined by fiber birefringence in the different sections of the MLPLG. We describe the conditions for the MLPLG to operate with automatic reciprocity leading to the possibility of phase-error-free operation.