Mid-infrared polarization rotator based on a Si3N4-CaF2 hybrid plasmonic waveguide with asymmetric metal claddings

An efficient and compact mid-infrared polarization splitter and rotator based on a bifurcated tapered-bent waveguide

We present predictive simulations for a novel mid-infrared (MIR) polarization splitter and rotator (PSR) design. It operates in the 3.1-3.6 [Formula: see text]m range, which is crucial for applications such as chemical and biological sensing, and environmental monitoring. This is the first report of a MIR PSR in this range on a SOI platform, enabling the generation of TE modes at both ports of the PSR. Our solution is particularly important since quantum cascade lasers are the optimal choice of source in the MIR, emitting linearly polarized light in the vertical direction that couples to transverse magnetic (TM) waveguide modes, necessitating conversion to transverse electric (TE) mode for compatibility with numerous on-chip devices optimized for TE mode. Our proposed PSR is designed to provide both TE modes at both ports of the bifurcated waveguide, showcasing outstanding performance characterized by low insertion loss, low TM to TE power conversion loss, and minimal crosstalk. It exhibits TE insertion loss and TM to TE power conversion loss of less than 0.5 dB over a 500 nm and 400 nm wavelength range, respectively, while maintaining crosstalk values below 20 dB over a broad wavelength range of 400 nm.

Experimental confirmation of self-imaging effect between guided light and surface plasmon polaritons in hybrid plasmonic waveguides

We fabricated a hybrid plasmonic device using self-imaging effect between guided light and surface plasmon polaritons in the hybrid plasmonic waveguide. The hybrid plasmonic device was fabricated by evaporating gold on the part of the silicon waveguide. Self-imaging was generated at the gold-covered section in the waveguide. Self-imaging of guided light and surface plasmon polaritons in hybrid plasmonic waveguides affect the output intensity of the hybrid plasmonic waveguide. The length of the hybrid plasmonic waveguide changes self-imaging conditions. We confirmed that the output intensity was affected by the length of the hybrid plasmonic waveguide. These findings contribute to the development of hybrid plasmonic devices and potentially improve integration density of hybrid photonic integrated circuits.

Thin-film lithium niobate polarization modulator without polarization diversity

With the development of photonic integrated circuits and optical information processing on thin-film lithium niobate (TFLN), the realization of the TFLN-based polarization device is becoming more and more crucial. Here, we demonstrate a polarization modulator on the TFLN platform without polarization diversity. Without polarization manipulation elements, the device only composes a phase modulator and a two-dimensional grating coupler. The structure features small footprint and high fabrication tolerance. The device holds promise for polarization encoding telecommunication.