New type of optical hysteresis

Drew N. Maywar, Govind Prasad Agrawal

We use spatial chirp of the built-in grating to improve optical bistability on reflection from distributed feedback semiconductor laser amplifiers. We show that improvements in the on-off switching ratio occur because spatial chirp greatly affects the saturation behavior of the reflectivity resonances, allowing access to states of low reflection during bistable switching. We also show that spatial chirp modifies the spectral range of the variety of hysteresis shapes that occur on reflection. In doing so, we discover a new type of hysteresis loop that reveals a qualitative difference between the loop-shaped hystereses occurring near the two edges of the stop band. With spatial chirp, the new hysteresis loop can exhibit an on-off switching ratio in excess of 100000.

Javier Munárriz Arrieta

Amitabh Joshi, Wenge Yang, Min Xiao

We experimentally demonstrate ‘backward’ hysteresis loop in optical bistability from an optical ring cavity containing three-level (Λ-type) rubidium atoms. Switching from ‘backward’ to normal hysteresis loop can be controlled by coupling field and cavity detuning.

Paul Mandel, Thomas Erneux

Nguyen Ba An, Le Thi Cat Tuong

Amitabh Joshi, Wenge Yang, Min Xiao

We have experimentally investigated dynamical hysteresis behavior by changing the sweeping frequency of the cavity input field in the optical bistability of rubidium atoms (in a three-level atomic-type configuration) inside an optical cavity. The shape, width (or area), and direction of the hysteresis cycle are sensitive functions of the sweeping frequency for such an optical bistable system.