In this paper, we show that anisotropic photosensitive nematic liquid crystals (PNLC) made by incorporating anisotropic absorbing dyes are promising candidates for constructing all-optical elements by virtue of the extraordinarily large optical nonlinearity of the nematic host. In particular, we have demonstrated several room-temperature 'prototype' PNLC-based all-optical devices such as optica...

We report on an all-optical AND-gate using simultaneous Four-Wave Mixing (FWM) and Cross-Gain Modulation (XGM) in a semiconductor optical amplifier (SOA). The operation of the proposed AND gate is simulated and the results demonstrate its effectiveness. This AND gate could provide a new possibility for all-optical computing and all-optical routing in future all-optical networks. In an AND ( AB ...

A simple all-optical logic device, composed of an SOA and an optical filter, is proposed. By utilizing optical filtering, multi-logic functions (AND, OR and XOR) are demonstrated at 10 Gb/s using the same setup, under different operation conditions. Simulations indicate that the device can operate at much higher bit rate. Introduction: All-optical logic gates have received considerable attentio...

We experimentally demonstrate and characterize a four-qubit linear-optical quantum logic circuit. Our robust and versatile scheme exploits encoding of two qubits into polarization and path degrees of single photons and involves two crossed inherently stable interferometers. This approach allows us to design a complex quantum logic circuit that combines a genuine four-qubit C(3)Z gate and severa...

We report coherent optical control of a biexciton (two electron-hole pairs), confined in a single quantum dot, that shows coherent oscillations similar to the excited-state Rabi flopping in an isolated atom. The pulse control of the biexciton dynamics, combined with previously demonstrated control of the single-exciton Rabi rotation, serves as the physical basis for a two-bit conditional quantu...

A classical logic gate connecting input and output light pulses is demonstrated. The gate operation is based on three steps: First, two incoming light pulses are stored in a Bose-Einstein condensate; second, atomic four-wave mixing generates a new matter wave; and third, the light pulses are retrieved. In the presence of the new matter wave, the retrieval generates a new optical wave. The latte...

Reversible logic has attracted significant attention in recent years. It has applications in low power CMOS, quantum computing, nanotechnology, and optical computing. Traditional gates such as AND, OR, and EXOR are not reversible. In fact NOT is the only reversible gate from the traditional set of gates. Several reversible gates have been proposed. Among them are the controlled NOT (also known ...