Integrated photonic convolution acceleration core for wearable devices

With the advancement of deep learning and neural networks,the computational demands for applications in wearable devices have grown exponentially.However,wearable devices also have strict requirements for long battery life,low power consumption,and compact size.In this work,we propose a scalable optoelectronic computing system based on an integrated optical convolution acceleration core.This system enables high-precision computation at the speed of light,achieving 7-bit accuracy while maintaining extremely low power consumption.It also demonstrates peak throughput of 3.2 TOPS(tera operations per second)in parallel processing.We have successfully demonstrated image convolution and the typical application of an interactive first-person perspective gesture recognition application based on depth information.The system achieves a comparable recognition accuracy to traditional electronic computation in all blind tests.

On-chip programmable pulse processor employing cascaded MZI-MRR structure

Optical pulse processor meets the urgent demand for high-speed,ultra wideband devices,which can avoid electrical confinements in various fields,e.g.,alloptical communication,optical computing technology,cohcrcnt control and microwave fields.To date,great efforts have been madc particularly in on-chip programmable pulse proccessing.Here,we experimentally demonstrate a programmable pulse proceesor employing 16cascaded Mach-Zehnder interferometer coupled microring resonator(MZI-MRR)structure based on silicon-oninsulator wafer.With micro-heaters loaded to the device,both amplitude and frequency tunings can be realized in each MZI-MRR unit.Thanks to its reconfigurability and integration ability,First,it can serve as a fractional differentiator whose tuning range is 0.51-2.23 with deviation no more than 7%.Second,the device can be tuned into a programmable optical filter whose bandwidth varies from 0.15to 0.97nm.The optical filter is also shape tunable.Especially,15-channel wavelength selective switches are generated.

Compact and broadband multimode waveguide bend by shape-optimizing with transformation optics

Multimode waveguide bend is one of the key components for realizing high-density mode-division multiplexing systems on chip.However,the reported multimode waveguide bends are either large,bandwidth-limited or fabrication-complicated,which hinders their applications in future high-density multimode photonic circuits.Here we propose a compact multimode waveguide bend supporting four TE modes simply by shape-optimizing with transformation optics.The shape of the waveguide is optimized in the virtual space with gradient distribution of the refractive index,so that the scattering loss and intermode cross talk are well suppressed.After conformal mapping back into the physical space,a compact(effective radius of 17μm)multimode bending waveguide is obtained.Simulations show that the proposed multimode waveguide bend has little loss(<0.1 dB)and low cross talk(<−20 dB)throughout an ultrabroad wavelength range of 1.16–1.66μm.We also fabricated the shape-optimized multimode bending waveguide on a silicon-on-insulator wafer.At 1550 nm wavelength,the measured excess losses for the four lowest-order TE modes are less than 0.6 dB,and the intermode cross talks are all below−17 dB.Our study paves the way for realizing high-density and large-scale multimode integrated optical circuits for optical interconnect.

Wideband adaptive microwave frequency identification using an integrated silicon photonic scanning filter

Photonic-assisted microwave frequency identification with distinct features, including wide frequency coverage and fast tunability, has been conceived as a key technique for applications such as cognitive radio and dynamic spectrum access. The implementations based on compact integrated photonic chips have exhibited distinct advantages in footprint miniaturization, light weight, and low power consumption, in stark contrast with discrete optical-fiber-based realization. However, reported chip-based instantaneous frequency measurements can only operate at a single-tone input, which stringently limits their practical applications that require wideband identification capability in modern RF and microwave applications. In this article, we demonstrate, for the first time, a wideband, adaptive microwave frequency identification solution based on a silicon photonic integrated chip,enabling the identification of different types of microwave signals from 1 to 30 GHz, including single-frequency,multiple-frequency, chirped-frequency, and frequency-hopping microwave signals, and even their combinations.The key component is a high Q-factor scanning filter based on a silicon microring resonator, which is used to implement frequency-to-time mapping. This demonstration opens the door to a monolithic silicon platform that makes possible a wideband, adaptive, and high-speed signal identification subsystem with a high resolution and a low size, weight, and power(SWaP) for mobile and avionic applications.

Silicon-based optoelectronics:progress towards large scale optoelectronic integration and applications

In the past half century,silicon-based microelectronics and optical fiber communication have triggered a far-reaching information technology revolution,which has moved human society into a high-speed information age.The demand for communication capacity and speed is growing exponentially.On the other hand,data center and high-performance computing are facing bottlenecks of speed,bandwidth,and energy consumption of electrical interconnections.