Gigabit Pulse Position Bistability in Semiconductor Lasers

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. © 1987, American Medical Association. All rights reserved.

Nonlinear optics in Silicon photonic crystal cavities

Silicon is known to be a very good material for the realization of high-Q, low-volume photonic cavities, but at the same it is usually considered as a poor material for nonlinear optical functionalities like second-harmonic generation, because its second-order nonlinear susceptibility vanishes in the dipole approximation. In this work we demonstrate that nonlinear optical effects in silicon nanocavities can be strongly enhanced and even become macroscopically observable. We employ photonic crystal nanocavities in silicon membranes that are optimized simultaneously for high quality factor and efficient coupling to an incoming beam in the far field. Using a low-power, continuous-wave laser at telecommunication wavelengths as a pump beam, we demonstrate simultaneous generation of second- and third harmonics in the visible region, which can be observed with a simple camera. The results are in good agreement with a theoretical model that treats third-harmonic generation as a bulk effect in the cavity region, and second-harmonic generation as a surface effect arising from the vertical hole sidewalls. Optical bistability is also observed in the silicon nanocavities and its physical mechanisms (optical, due to two-photon generation of free carriers, as well as thermal) are investigated. © 2011 IEEE.

Optically triggered polarisation bistability in GaInAsP twin stripe injection lasers using integrated devices

A bistable polarization switching element and optical triggering source has been produced by etching a facet in a twin stripe semiconductor laser. The switching element is formed by a pair of stripe segments at one end of the device and triggered with short light pulses from the other two segments. Detector limited switching risetimes have been measured at 250 ps.

Bistability in silicon microring resonator based on strain induced by a piezoelectric lead zirconate titanate thin film

We demonstrate bistability in a submicron silicon optical phase shifter based on the photoelastic effect. The strain magnitude is electrically controlled by a piezoelectric thin film placed on top of the device. The hysteresis behavior of the piezoelectric response shows potential application as bistable device independent of the optical intensity. © 2012 American Institute of Physics.