Reconfigurable photonic RF filter based on opto-VLSI processing

In this paper, a novel reconfigurable 5-tap photonic RF filter based on Opto-VLSI processor is proposed where an Opto-VLSI processor is used in conjunction with a 5-fibre Bragg grating (FBG) array to slice the spectrum of a broad band light source, thus achieving commensurate true-time delays and variable tap weights. The proposed photonic RF filterstructure is experimentally demonstrated by means of several examples which show the capability of the Opto-VLSI processor to synthesise transversal RF filter responses with adaptive weights

Dynamic Spot Generation Using Opto-VLSI Processing

In this paper we demonstrate the capability of OptoVLSI processors to generate arbitrary optical power distribution for adaptive optical beam splitting and dynamic optical spot generation. By using the multicasting capability of Opto-VLSI processors, an input optical signal can be dynamically split into N spots array, and the output power of each spot can be independently configured. Experimental results of multiple beam splitting show that dynamic optical multicasting can be achieved with more than 20dB dynamic range. Special patterns are also generated by optimising the phase hologram of the Opto-VLSI processor to place the output beam spots at appropriate positions

Optical Cavity Design of Integrated MicroPhotonic Wideband Adaptive RF Signal Processor

In this paper. we analyse the beam propagation within the optical cavities of all integrated MicroPhotonic adaptive RF signal processor, and optimize the optical beam diameter and incidence angle that maximize the number of taps to realise high-resolution R F processor. Simulation results show that for a 1m-diameter collimated Gallssioll beam, 16 taps per cavity can be achieved for a 20mm-long cavity, and that there is no need for a diffractive optical element (DOE) to re- collimate the Gaussian beam within the cavity. The tolerance of the MicrnPhotonic processor to changes in optical cavity length which degrade the beam overlapping with the active areas of the photodetector elements, is also quantitatively analysed

Dynamic wavefront generation technology using OptoVLSI processor

In this paper we present a novel approach for dynamic wavefront generatio based on reconfigurable Opto-VLSI processing. Computer algorithms are developed to generate arbitrary quadric-phse lense and lenslet array with programmable focal lenght, beam steering and lens diameter by driving the Opto-VLSI processor with different computer generated phase holograms. Proff-of-concept experimental results show that multiple spheric and aspheric lens/lenslet wavefrongs can be generated with each lens independently addressed. The measured meaximum focal length tuning range is from +80mm to infinity and the beam scanning angular range is +7mrad, which are in excellent agreement with theory. Difference spatial profiles for wavefront correction are also experimentally demonstrated

Adaptive Prompt Learning with Distilled Connective Knowledge for Implicit Discourse Relation Recognition

Implicit discourse relation recognition (IDRR) aims at recognizing the discourse relation between two text segments without an explicit connective. Recently, the prompt learning has just been applied to the IDRR task with great performance improvements over various neural network-based approaches. However, the discrete nature of the state-art-of-art prompting approach requires manual design of templates and answers, a big hurdle for its practical applications. In this paper, we propose a continuous version of prompt learning together with connective knowledge distillation, called AdaptPrompt, to reduce manual design efforts via continuous prompting while further improving performance via knowledge transfer. In particular, we design and train a few virtual tokens to form continuous templates and automatically select the most suitable one by gradient search in the embedding space. We also design an answer-relation mapping rule to generate a few virtual answers as the answer space. Furthermore, we notice the importance of annotated connectives in the training dataset and design a teacher-student architecture for knowledge transfer. Experiments on the up-to-date PDTB Corpus V3.0 validate our design objectives in terms of the better relation recognition performance over the state-of-the-art competitors

Demonstration of Tunable Optical Notch Filter Using 1-D Opto-VLSI Processor

An opto-very-large-scale-integrated (opto-VLSI)-based tunable optical filter structure is demonstrated. Filter tunability is achieved by reconfiguring the holographic diffraction grating of an opto-VLSI processor, allowing virtually any type of filter response to be synthesized. A proof-of-concept tunable notch filter with wavelength span of 7 nm is experimentally verifie

Optical Interference Suppression using MicroPhotonic RF Filter Structure

The impact of laser coherence noise on conventional photonic RF filters is investigated in this paper. In addition, a new microphotonic adaptive RF filter structure is proposed, which can simultaneously suppress the phased-induced intensity noise caused by optical interference. Results show that the coherence length of the laser light significantly degrades the RF frequency response of a photonic transversal RF filter, whereas the microphotonic RF filter has the capability of generating arbitrary transfer function with no phase-induced intensity nois

Dynamic optical comb filter using opto-VLSI processing

Reconfigurable multi-channel optical filters are presented in this paper. The operation principle of the reconfigurable filter is based on the dynamic beam steering capacity of Opto-VLSI processor in conjunction with a high dispersion free space grating. The dispersion grating separates the input signal spectrum while the Opto-VLSI processor is driven by optimised phase holograms to dynamically select the wavelengths to be coupled into the output port. Experimental results show that up to 8 bands can be synthesised, with a wavelength tuning span of 10 nm and a 3dB bandwidth less than 0.5nm