Fengguang Luo

Optical perfect-shuffle-exchange interconnection network using a liquid-crystal spatial light switch.

The perfect-shuffle-exchange interconnection network (e.g., the omega network) is a type of free-space regular multistage interconnection network. An equivalent omega network that consists of left- and right-perfect-shuffle interconnects as well as spatial light switch devices is described. An optical omega network that uses two special polarization prisms and a liquid-crystal spatial light switch is presented. The experimental results of a 8 x 8 omega network are reported. The optical omega network has the features of simple architecture and ease of integration.

RAMAN AMPLIFICATION AND SUPERLUMINAL PROPAGATION OF ULTRAFAST PULSES BASED ON LOOP SILICON WAVEGUIDES: THEORETICAL MODELING AND PERFORMANCE

In this paper, we report, for the first time to the best of our knowledge, the detailed modeling and performance of Raman amplification and superluminal propagation of weak ultrafast femtosecond optical pulses in nonlinear loop single mode silicon-oninsulator anomalously dispersive optical waveguides. Using the device, theoretical results for 100-fs signal optical pulse show that when the launch peak power of signal pulse is fixed at −10 dBm, the gain value up to 30 dB can be achieved, and the delay time of superluminal propagation can also be adjusted by changing the system parameters, including initial chirp and peak power of pump pulse, initial delay time between pump and signal pulses, and waveguide length, etc.

Light waveguide electro-optical printed circuit board

The configuration of polymer light waveguide electro-optical printed circuit board(EOPCB) is proposed in this paper. An additional optical layer with light waveguide structure is used in conventional PCB to construct EOPCB. Light waveguide core layer mould is made with SU-8 photolithograph. Polymer light waveguide layer which is embedded between multiplayer PCB is made in experiment by Doctor-blading technology for large size application. Vertical cavity surface emitting laser (VCSEL) array is used as optical transmitter array. PIN photodiode array is used as optical receiver array. A MT-compatible direct coupling method is presented to couple light beam between optical transmitter/receiver with light waveguide layer. The optical signals from a processor element chip on the PCB can transmit to another processor element chip on the same PCB board through light waveguide interconnection in EOPCB. So optical interconnection between chip to chip for parallel multiprocessor system can be reailzed by EOPCB.

Parallel-stage-based reconfigurable optical add-drop multiplexer for WDM optical transport networks

This letter proposes a simple and flexible reconfigurable optical add-drop multiplexer (ROADM) based on parallel-stage configuration using Mach-Zehnder-based fiber gratings, 1times2 optical switches, and Y-model combiners. The proposed ROADM with four-stage parallel configuration is designed and experimentally investigated to show its performance in full wavelength selection and advantages in reducing the discrepancy of the insertion loss between channels and upgrading

Recirculating implementation of the optical segmental Banyan network

We propose a novel technique for recirculating implementation of optical Banyan (butterfly) interconnection networks. The key concept is that two-dimensional segmental input/output patterns, rather than the conventional one-dimensional ones, are employed. This arrangement ensures that the two channels in a switching pair are always located at adjacent positions, which then leads to an efficient selection between the straight and the Banyan connection. As Banyan networks do not possess identical cascade stages, special rearrangement of the output channels is required in each stage so as to satisfy the requirement of recirculating implementation. This can be achieved by hybrid optoelectronic or all-optical means. If reconfigurable spatial light modulators are used, multistage Banyan networks can be realized by a single-stage optical set-up in a recirculating manner.

Electro-optic chaotic system based on the reverse-time chaos theory and a nonlinear hybrid feedback loop

A novel electro-optic chaos source is proposed on the basis of the reverse-time chaos theory and an analog-digital hybrid feedback loop. The analog output of the system can be determined by the numeric states of shift registers, which makes the system robust and easy to control. The dynamical properties as well as the complexity dependence on the feedback parameters are investigated in detail. The correlation characteristics of the system are also studied. Two improving strategies which were established in digital field and analog field are proposed to conceal the time-delay signature. The proposed scheme has the potential to be used in radar and optical secure communication systems.

A novel routing optical matrix swtiching method

Abstract A routing optical matrix switching method which constitutes of a novel nonblocking routing optical Crossbar network system is presented. The routing optical Crossbar network includes two parts: one is a routing fan-out unit which provides multi-optical channels for each input light beam, and the other is a routing fan-in unit which combines the optical channels with the same destination output port into one. A module of 4×4 routing optical matrix switching module was developed by this method, which is as well applicable to 2×2,8×8, etc. These optical matrix switches can widely be used in the field of DWDM communications.

Thermal stability analysis of nonlinear optical switch based on asymmetric three-core nonlinear directional coupler with variable Gaussian coupling coefficient

We analyze the thermal stability of the power transmission efficiency and the extinction ratio in an asymmetric three-core silicon-on- insulator nonlinear directional coupler with variable Gaussian coupling coefficient. Because the refractive indices of Si and SiO2 materials are subject to temperature change, the effective refractive index of the non- linear coupler varies correspondingly. When ratio (LC/b) andT change, the relative transmission efficiency error (� ) values and relative change of extinction ratio (η) values are obtained. It can be easily shown that vari- ation ofand η are negligible under LC/b ≤ 1/2. Therefore, we can set LC/b ≤ 1/2 andT ∈ (-100 K, 100 K) in order to make the power transmis- sion efficiency and the extinction ratio work steadily. This is significant in guiding an actual nonlinear optical pulse switch fabrication. C � 2011 Society

A new design of WDM-based optical inter-satellite links in modern small satellite constellations

Through the detail analysis of inter-satellites links in modern small satellite constellations, a new optical filters-based four-channel wavelength division multiplexer was designed and fabricated. This WDM device working at 0.85, 1.06, 1.31 and 1.55μm is designed to build an optical inter-satellites link, which provide two data streams at 0.85 and 1.55μm, an inter-satellite tracking channel at 1.06μm, and an different orbit communication channel at 1.31μm. Through experiments, we got the channel download efficiencies at 0.85, 1.06, 1.31 and 1.55μm are 49.7%, 42.3%, 33.4% and 25.1% and the channel interval is 5mm. The features of small size and light weight make this WDM device quite attractive for space borne applications and the big channel interval could also accommodate the wavelength shifts due to Doppler Effect, temperature variations and radiation effects in space.

Design and fabrication of an optical interleaver with cascaded multimode interference couplers

A lattice-form optical interleaver was designed and fabricated with a silicon-based silica waveguide. Cascaded multimode interference couplers were first employed in the lattice circuit and helped to relax the fabrication tolerance. The device shows good performance, the insertion loss is less than 2.25 dB, the passband ripple is less than 0.15 dB, the cross talk is less than -18.9 dB, and the 0.5 dB passband is more than 100 GHz.