Wayne F. Sharfin

Bistable Diode Laser Amplifiers In High Performance Optical Communication And Optical Computing Systems

The physics of low energy switching in both optical and electronic devices is briefly introduced. The properties and applications of bistable diode amplifiers are reviewed. It is stressed that bistable dode laser amplifiers are the most energy efficient optical switching devices so far demonstrated. The concept of colored optical interconnects is introduced for applications in closely spaced wavelength division multiplexing transmission systems. The implementation of a generalized, optically updatable, optical crossbar switch is discussed.

The role of nonlinear diode laser amplifiers in optical processors and interconnects

The advantages to be gained from the use of optical processors and interconnects for hybrid electronic/optical signal processing networks are first presented. The physics of nonlinear diode laser amplifiers is then examined in the context of optical thresholding and logic. Specific examples of the use of these devices in simple optical processors and interconnects are proposed. The technology required for realization of arrays of laser amplifiers for the proposed applications is finally discussed.

Extremely Low Switching Energy Optical Bistable Devices

An all-optical bistable device and an electro-optical bistable device, with performances approaching the fundamental statistical limits, are described. In the all-optical approach, the giant nonlinearities associated with bound excitons in CdS are exploited to demonstrate the lowest-switching-energy (< 4 pJ) all-optical bistable device. The device switches in less than 1 ns and fully recovers in less than 2 ns. These times are detector limited. A switching energy of less than 1 fJ is theoretically predicted for an optimized geometry. In the electro-optical approach, an InGaAsP/InP diode laser amplifier is used to demonstrate bistability with less than 6000 photons (< 8 X 10-16 J) incident on the device. The device switches in less than 1 ns and is cascadable since it has a gain of 100. It operates at room temperature and is compatible with diode laser sources.

Physics Of Low Energy Optical Switching

The physics of low-energy optical switching in both ideal and experimental devices is discussed. Guided-wave optical bistable devices are predicted to have the lowest switching energy per unit gain of any optical switching devices. So far, the bistable diode laser amplifier is the only optical device which can switch with the same switching efficiency as the best electronic device.

Bistable Diode Laser Amplifiers In Optical Computing

The role of bistable diode laser amplifiers in optical signal processing and optical computing is discussed. A lower bound (1 pJ) on the switching energy of all-optical unguided bistable devices is obtained. Optical guided wave devices, both active and passive, promise to have the lowest switching energy. The advantages and limitations of electronic devices are presented. It is concluded that optics has important advantages over electronics in highly interconnected systems. Bistable diode laser amplifiers have the lowest demonstrated switching energy per unit gain (300 fJ) of any optical devices operating at room temperature. Application of these devices in an updatable optical crossbar switch leads to unique capabilities. Optics has significant advantages over electronics even for matrices of modest sizes (32x32).