An ultra-compact dual-channel multimode wavelength demultiplexer based on inverse design

TL;DR: In this paper , a photonic emulator that uses light propagation instead of electromagnetic simulation is proposed to enable high-precision reconfiguration of the design target on the basis of precise tuning of the effective refractive index near the pixels in the design area and fast feedback of the optical response.

TL;DR: In this paper , a review is given for recent progresses of high-performance silicon polarization-handling devices assisted with subwavelength structures (SWSs), which introduce more degrees of freedom (DoFs) in design.

Abstract: Inverse design has been widely studied as an efficient method to reduce footprint and improve performance for integrated silicon photonic (SiP) devices. In this study, we have used inverse design to develop a series of ultra-compact dual-band wavelength demultiplexing power splitters (WDPSs) that can simultaneously perform both wavelength demultiplexing and 1:1 optical power splitting. These WDPSs could facilitate the potential coexistence of dual-band passive optical networks (PONs). The design is performed on a standard silicon-on-insulator (SOI) platform using, what we believe to be, a novel two-step direct binary search (TS-DBS) method and the impact of different hyperparameters related to the physical structure and the optimization algorithm is analyzed in detail. Our inverse-designed WDPS with a minimum feature size of 130 nm achieves a 12.77-times reduction in footprint and a slight increase in performance compared with the forward-designed WDPS. We utilize the optimal combination of hyperparameters to design another WDPS with a minimum feature size reduced to 65 nm, which achieves ultra-low insertion losses of 0.36 dB and 0.37 dB and crosstalk values of -19.91 dB and -17.02 dB at wavelength channels of 1310 nm and 1550 nm, respectively. To the best of our knowledge, the hyperparameters of optimization-based inverse design are systematically discussed for the first time. Our work demonstrates that appropriate setting of hyperparameters greatly improves device performance, throwing light on the manipulation of hyperparameters for future inverse design.

TL;DR: This article designs an adder and an ordinary differential equation solver (ODE) on chip by Fourier optics and metasurface techniques and designs a signal generator that can achieve power splitting with the phase difference of π between the two output waveguides.

TL;DR: In this paper, the authors studied the mode-conversion behavior of branching or separating planar-dielectric waveguides as a function of branch asymmetry and taper slope.

TL;DR: This filterbank is suitable for on-chip wavelength-division-multiplexing (WDM) applications, and has the largest-to-date reported number of channels built on an SOI platform.

TL;DR: The progress toward and prospects for the penetration of optics all the way to the silicon chip are summarized.

TL;DR: In this paper, the authors present ultracompact integrated optical echelle grating wavelength division multiplexing (de) multiplexers for on-chip optical networks, fabricated using high-index-contrast silicon-on-insulator photonic waveguide technology.