Heterogeneous Integrated Photonics for Nonlinear Frequency Conversion and Polarization Diversity

Silicon has proven to be one of the materials of choice for many integrated photonic applications. However, silicon photonics is limited by certain material shortcomings. Two shortcomings addressed in this work are zero second-order optical nonlinearity, and the lack of methods available to achieve broadband polarization diversity. Heterogeneous integrated solutions for these shortcomings of silicon photonics are presented in this work. First, nonlinear frequency conversion is demonstrated with thin-film lithium niobate on silicon substrates. The method for reaching the highest-achieved second-harmonic generation conversion efficiency, using active monitoring during periodic poling, is discussed. Additionally, a cascaded approach for generating higher-order harmonics is presented, along with a theoretical model to extract conversion efficiencies from measurements performed with pulsed sources. Initial work to integrate second-order and third-order nonlinearities together using thin-film lithium niobate and chalcogenide is also presented. Second, a spatially-mapped anisotropic material platform that exhibits broadband polarization diversity is discussed. This platform currently demonstrates polarization beam splitters, and polarization-selective beam taps and microring resonators, whose results are presented. Also discussed is a method to include polarization rotators to demonstrate full polarization diversity, as well as designs and initial work to expand the platform to operate at longer wavelengths, specifically those in the telecom band

Integrated Polarization-Selective Microring Resonators And Beam Taps Via Topographically Anisotropic Photonics

Topographically anisotropic photonics is used to demonstrate polarizationselective microring resonators and beam taps. Both fabricated devices exhibit strong polarization-selectivity. The beam tap is shown to be broadband, as it retains this selectivity over a bandwidth of over 80 nm

Damascene-Patterned Optical Anisotropy In Integrated Photonics

We propose, simulate and experimentally demonstrate a method for realizing spatially-mapped birefringence onto integrated photonic devices and circuits. The fabrication method is based on applying a damascene-like process to dielectric film stacks to form anisotropic optical waveguides. An integrated polarizing beam-splitter (PBS) is realized with unprecedented performance: a record 0.52 octaves of fractional bandwidth (116 THz), maximum on-chip insertion loss of 1.4 ± 0.8 dB, and a minimum extinction ratio of 16 ± 3 dB, pushing it into the realm of wideband spectroscopy and imaging applications. Additionally, photonic structures such as polarization-selective beam-taps and polarization-selective microring resonators are demonstrated

Integrated Polarization Beam-Splitter With 116 Thz Bandwidth Via Topographically Anisotropic Photonics

Topographically anisotropic integrated photonics is proposed for extremely broadband polarization-selective devices. Polarization beam-splitting with an unprecedented 116 THz of bandwidth (0.52 octaves), insertion losses \u3c1.2 dB and extinction ratio \u3e16 dB is experimentally demonstrated

Integrated Polarization Beam-Splitter With 116 Thz Bandwidth Via Topographically Anisotropic Photonics

Topographically anisotropic integrated photonics is proposed for extremely broadband polarization-selective devices. Polarization beam-splitting with an unprecedented 116 THz of bandwidth (0.52 octaves), insertion losses \u3c1.2 dB and extinction ratio \u3e16 dB is experimentally demonstrated

A Multiple Source and Target Sweeping Method for Generating All Hexahedral Finite Element Meshes

: This paper presents an algorithm to enhance the capabilities of generating all hexahedral finite element meshes by the sweeping process. Traditional sweeping techniques are very useful and robust. They create meshes by projecting an existing single-surface mesh along a specified trajectory to a specified singletarget surface. In this process the source surface is meshed by any surface meshing algorithm while the sides that couple the source to the target are limited to a regular mapped quadrilateral mesh. This process is often called two and one half dimensional meshing. The procedure presented in this paper enhances this traditional technique by developing a projection technique that minimizes mesh distortion; and allows multiple connected surfaces to single target, multiple unconnected surfaces to single target, and multiple unconnected surfaces to multiple unconnected target sweeping. Keywords: Sweeping, Hexahedrons, Multiple Targets 1. Introduction Swept representations are base..

Random Quasi-Phase-Matching On A Nanophotonic Heterogeneous Silicon Chip

We demonstrate grating-assisted random quasi-phase-matching in unpoled thin-film lithium niobate waveguides on a silicon substrate via second-harmonic generation from near-infrared to visible wavelengths