Optical mode manipulation using deep spatial diffractive neural networks.

In this paper, we investigate the theoretical models and potential applications of spatial diffractive neural network (SDNN) structures, with a particular focus on mode manipulation. Our research introduces a novel diffractive transmission simulation method that employs matrix multiplication, alongside a parameter optimization algorithm based on neural network gradient descent. This approach facilitates a comprehensive understanding of the light field manipulation capabilities inherent to SDNNs.

Releasing the light field in subwavelength grating slot microring resonators for athermal and sensing applications.

Silicon-on-insulator (SOI) platforms have attracted increasing interest for photonic integrated devices with an ultra-small footprint. The distinct feature is the strong light confinement in the silicon region due to a high refractive-index-contrast. In contrast, releasing the light field out of the silicon region is also of great significance for providing a useful supplement to existing light guiding mechanisms and for facilitating versatile applications.

Reconfigurable and tunable compact comb filter and (de)interleaver on silicon platform.

We propose and demonstrate a reconfigurable and tunable chip-scale comb filter and (de)interleaver on a silicon platform. The silicon-based photonic integrated device is formed by Sagnac loop mirrors (SLMs) with directional couplers replaced by multi-mode interference (MMI) assisted tunable Mach-Zehnder interferometer (MZI) couplers. The device can be regarded as a large SLM incorporating two small SLMs which form a Fabry-Perot (FP) cavity.

Compact tunable electromagnetically induced transparency and Fano resonance on silicon platform.

We propose and demonstrate an on-chip coupling resonant system to generate electromagnetically induced transparency (EIT)-like effect and Fano resonance on silicon platform. It is composed of a microring resonator (MRR) and two cascaded Sagnac-loop mirrors (SLMs) assisted Fabry-Perot (FP) cavity on silicon-on-insulator. According to the coupling conditions of the MRR, two cases are studied theoretically.

Subwavelength grating slot (SWGS) waveguide on silicon platform.

We present a subwavelength grating slot (SWGS) waveguide on silicon platform. The SWGS waveguide is characterized by the merging of a slot structure and a subwavelength grating (SWG) structure. The mode guiding mechanism (SWG slot mode) relies on the combination of surface enhanced supermode (slot mode) in a slot waveguide and Bloch mode (SWG mode) in an SWG waveguide.

Compact tunable photonic comb filter on a silicon platform.

We propose and demonstrate a compact wavelength- and bandwidth-tunable photonic comb filter on a silicon platform. It is a Fabry-Perot (FP) cavity fabricated on silicon-on-insulator, which is composed of two cascaded Sagnac loop mirrors (SLMs) with multimode-interferometer-assisted Mach-Zehnder interferometer (MZI) couplers. The effective length of the FP cavity and the reflectivity of the SLMs can be dynamically changed based on thermal-optical effects by tuning three phase shifters along the cavity length and MZI arms, leading to center wavelength tuning and bandwidth tuning of the comb filter.

Graphene-silicon microring resonator enhanced all-optical up and down wavelength conversion of QPSK signal.

We fabricate a nonlinear optical device based on graphene-silicon microring resonator (GSMR). Using such graphene-assisted nonlinear optical device, we experimentally demonstrate up and down wavelength conversion of a 10-Gbaud quadrature phase-shift keying (QPSK) signal by exploiting degenerate four-wave mixing (FWM) progress in the fabricated GSMR. We study the conversion efficiency as a function of the pump power.