Fast-light enhancement of an optical cavity by polarization mode coupling

Abstract

We present an entirely linear all-optical method of cavity scale factor enhancement that relies on mode coupling between the orthogonal polarization modes of a single optical cavity, eliminating the necessity of using an atomic medium to produce the required anomalous dispersion, which decreases the dependence of the scale factor on temperature and increases signal-to-noise ratio by reducing absorption and nonlinear effects. The use of a single cavity results in common mode rejection of the noise and drift that would be present in a system of two coupled cavities. We show that the scale-factor-to-mode-width ratio is increased above unity for this system, and demonstrate tuning of the scale factor by (i) directly varying the polarization mode coupling via rotation of an intracavity half-wave plate, and (ii) coherent control of the cavity reflectance which is achieved simply by varying the incident polarization superposition. These tuning methods allow us to closely approach the critical anomalous dispersion condition and achieve unprecedented enhancements in scale factor and in the scale-factor-to-mode-width ratio. Based on these findings, we propose an adaptation of the traditional optical cavity gyroscope that takes advantage of polarization mode coupling to enhance the gyro scale factor, and demonstrate how the bandwidth of the scale factor enhancement for this gyroscope can be effectively broadened in comparison with fast-light gyroscopes based on atomic media.

Impact of resonant dispersion on the sensitivity of intracavity phase interferometry and laser gyros

“…Narrow bandwidth implies long pulses or cw radiation, where most of the research in this field has focused. For instance, theoretical estimates have found that large dψ/dΩ can be produced by two-peak gain and coupled resonators [11,12], or by an atomic medium [13]. The latter property has been verified experimentally.…”

On-chip tunable dispersion in a ring laser gyroscope for enhanced rotation sensing

“…Moreover, the structure of DPER-MZI laser gyro in our paper can be modulated and demodulated by the frequency difference signal according to similar schematic in [36].…”

Fast-Light Enhanced Brillouin Laser Based Active Fiber Optic Sensor for Simultaneous Measurement of Rotation and Strain

“…Recently, much theoretical and experimental work [1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16] has been carried out for enhancing the sensitivity of such devices using the superluminal effect. These studies considered both passive [1,3,4,5,6,7,9,10,12,13,14,15] and active [1,2,3,4,5,6,8,9,11,12] versions of the resonators. Furthermore, different physical mechanisms have been considered, in both active and passive cases, for realizing the anomalous dispersion that produces the superluminal effect.…”