Study of bistable optical devices using intensity coupled high gain lasers. Theoretical and experimental aspects

A. Daunois, J.-Y. Bigot, J. B. Grün

The switching dynamics of thermally induced optical bistability in ZnSe nonlinear interference filters is investigated experimentally and theoretically. The device, maintained on its low transmission level by a cw argon laser beam, is switched on its high transmission level by an external light pulse. Either a very fast switching or an important slowing down are obtained when the holding cw intensity or the switching pulse energy are well chosen. This variation of the switching times is analyzed theoretically and observed experimentally.

Ian H. White

Matthew Adams

Lixue Chen

Traditional frequency domain optical bistability(FDOB) devices with hybrid electro-optical feedback have low response speed and high noise fluctuations.Hence,a novel tunable laser FDOB device with an all-optical feedback was developed using a nonlinear fiber ring resonator as the frequency feedback element.Parametric equations of optical bistability were established according to the system's response to nonlinear process and frequency-dependent feedback.Based on the parametric equations,the characteristics and controllable operations of FDOB were analyzed.The switching response speed of the optical bistability was discussed.The analysis showed that the proposed all-fiber laser bistability device can effectively achieve intensity-driven and gain-driven optical bistability.The position and shape of the bistability hysteresis curve vary with the adjustment of gain or loss in the fiber ring resonator,hence realizing the controlled all-optical bistability operations.Sudden jumping of optical bistability in the frequency domain can be applied to monitor laser wavelength shift and achieve sensoring.The optical bistability response time is in the nanosecond order of magnitude and bistability switching is ultrafast.

Dominic F. G. Gallagher, Ian H. White, J.E. Carroll +1 more

The paper briefly reviews the major forms of optical bistability in active optical devices compatible for use in gigabit optical communication systems, and reports an entirely new optical bistability for the first time. Unlike previous devices, the two bistable states of the optical device are each a series of picosecond optical pulses at 1 GHz or greater repetition rates, and are distinguished by a half period temporal shift between their temporal positions in relation to a clock pulse. The bistable device is based on a gain switched semiconductor laser. Theoretical studies suggest 100-ps switching speeds might be achieved, and experimental results are reported indicating optically triggered switching times of 500 ps.

Ewan M. Wright