No abstract

Analog optical computing (AOC) has attracted great attention over the past few years, because of its ultra-high speed (potential for real-time processing), ultra-low power consumption, and parallel processing capabilities. In this article, we design an adder and an ordinary differential equation solver (ODE) on chip by Fourier optics and metasurface techniques. The device uses the 4f system consisting of two metalenses on both sides and one middle metasurface (MMS) as the basic structure. The MMS that performs the computing is the core of the device and can be designed for different applications, i.e., the adder and ODE solver in this article. For the adder, through the comparison of the two input and output signals, the effect of the addition can be clearly displayed. For the ODE solver, as a proof-of-concept demonstration, a representative optical signal is well integrated into the desired output distribution. The simulation result fits well with the theoretical expectation, and the similarity coefficient is 98.28%. This solution has the potential to realize more complex and high-speed artificial intelligence computing. Meanwhile, based on the direct-binary-search (DBS) algorithm, we design a signal generator that can achieve power splitting with the phase difference of π between the two output waveguides. The signal generator with the insertion loss of −1.43 dB has an ultra-compact footprint of 3.6 μm× 3.6 μm. It can generate a kind of input signal for experimental verification to replace the hundreds of micrometers of signal generator composed of a multi-mode interference (MMI) combination used in the verification of this type of device in the past.

In solar applications, the solar absorber is paramount to converting solar radiation to heat energy. We systematically examined the relationship between the efficiency of the solar absorber and operating temperature and other factors. By combining inverse designs with surface plasmonic and Fabry-Perot cavity solar absorption theories, we have developed several solar absorber devices with excellent performance at different temperatures. One of these devices displays a solar spectral absorption of 95.6%, an ultra-low emission rate of 5.7%, and optical-to-thermal conversion efficiency exceeding 90%, all within an ultra-thin depth of 0.45 μm under working temperatures of 600 K. The device has the potential to surpass the Shockley-Queisser limit (S-Q limit) in solar power generation systems. Our method is adaptable, enabling the design of optimal-performance devices to the greatest extent possible. The design was optimized using modern optimization algorithms to meet complex conditions and offers new insights for further study of the conversion from solar to thermal energy and the advancement of solar energy applications.

The optical coupler can couple the light from the fiber into the waveguide, and the wavelength demultiplexer can split light into different wavelengths. Both devices play a very important role in optical chips, and combing them together can further reduce the chip footprint and improve the operating efficiency. In this work, based on the direct-binary-search (DBS) inverse design algorithm, we design two metamaterial couplers that can realize multi-wavelength demultiplexing. The two devices are based on silicon on insulator (SOI) and cover an ultra-compact footprint of 3.6 μm × 3.6 μm. The first device can couple and split 1310 nm and 1550 nm light into two separate waveguides with the coupling efficiencies of 0.26 and 0.27, respectively. The second device can couple and split 1310 nm ,1490 nm and 1550 nm light into three separate waveguides with the coupling efficiencies of 0.25, 0.2 and 0.23，respectively. The large number of guide-mode resonances in the device leads to this effect. The two couplers, especially for the three-wavelength demultiplexing coupler, can be used as splitter for monolithically silicon integrated transceivers at the main optical fiber communication wavelength of 1310 nm, 1490 nm and 1550 nm, which potentially meets the low-cost and ultra-compact requirements for future passive optical networks.

Coupled resonant optical waveguide (CROW) gyroscope is an important type of integrated optical gyroscope based on Sagnac effect. However, the traditional CROW design method relying on empirical adjustment of parameters is deficient in achieving its best capability and the poor Sagnac effect of micro-scale devices leads to unsatisfactory performance of integrated devices. Therefore, the present study proposes a new approach to design CROW gyroscope by applying intelligent optimization algorithm(PSO: particle swarm algorithm) to design CROW gyroscope. Three aspects of work will be explored: Fristly, a new evaluation index is proposed to evaluate the efficiency of integrated optical gyroscope area utilization(EGA); Secondly, The performance limits for different losses and the accuracy limits and related parameters that can be achieved by increasing the resonator area at different losses are also explored. Finaly, we designed theoretical performance(The angle random walk) up to 29.1𝑑𝑒𝑔/√ℎ and only 1mm × 1mm in size.