arXiv subjects

Archana Kaushalram

Publications and source records attributed to Archana Kaushalram.

4 recordsLinked to original sources

arXiv2026

Toward Topology-Optimized Foundry PDKs: A Seeded Design Framework for Multimode Interferometers

We present an end-to-end design methodology for multimode interferometer (MMI)-based photonic devices that combines parameter optimization (PO) on analytical models with seeded topology optimization (TO) to maximize performance while preserving foundry design-rule compliance. A PO seed device is further refined via seeded TO, accessing a larger design space than analytical or parameterized methods alone can reach. We validate this pipeline on a 1x2 splitter, a TE modal multiplexer, and a polarization splitter, fabricating and measuring the first two on a commercial foundry process. Seeded TO reduces the measured insertion loss of the 1x2 splitter from 0.20 to 0.14 dB and improves TE00 transmission of the modal multiplexer from -2.79 to -1.01 dB over O-band. Applying this pipeline to a commercial foundry process design kit (PDK)-provided 1x2 and 2x2 splitter improves simulated transmission and tightens the 2x2 splitting ratio from 0.524 to 0.506, along with improved fabrication robustness, offering a practical, foundry-validated route toward incorporating TO-designed components into commercial PDKs.

physics.optics↗

arXiv2025

Integrated Photonic Topology Optimization with Nonvertical Sidewall Profiles: Applications in Lithium Niobate and Silicon

We enable density-based topology optimization (TO) to design integrated photonic devices featuring nonvertical sidewall profiles. Specifically, we demonstrate TO for fabrication processes with slanted sidewalls which are often used to enhance vertical coupling efficiency and fabrication processes with angled sidewalls which are a common feature of etching. The techniques demonstrated are readily adaptable to other etch profiles such as asymmetric or nonlinear. The enhancements are compatible with existing TO techniques, lengthscale constraints and multi-layer designs, and any dielectric materials, suiting the techniques for both academic and commercial foundry fabrications. We demonstrated the developed capabilities by designing slanted and angled silicon grating couplers and thin-film lithium niobate on insulator dual-polarization s-bends.

physics.optics↗

arXiv2024

Inverse-Designed Tapers for Compact Conversion Between Single-Mode and Wide Waveguides

Waveguide tapers are critical components for leveraging the benefits of both single-mode and wide waveguides. Adiabatic tapers are typically hundreds of microns in length, dramatically limiting density and scalability. We reenvision the taper design process in an inverse-design paradigm, introducing the novel L-taper. We present a novel approach to inverse-designed tapers where the input and output waveguides are rotated 90 degrees with respect to each other. The resultant design has an order-of-magnitude smaller footprint, and the design process is compatible with a variety of fabrication processes. We demonstrate an L-taper designed on 220 nm silicon-on-insulator that converts a 0.5 micron waveguide to a 12 micron waveguide with -0.38 dB transmission and 40 nm 1-dB bandwidth. The footprint is 16 micron by 6 micron, representing a 12x smaller footprint than a linear taper with the same transmission.

physics.optics↗

arXiv2022

Integrated Photonic Platforms for Quantum Technology: A Review

Quantum information processing has conceptually changed the way we process and transmit information. Quantum physics, which explains the strange behaviour of matter at the microscopic dimensions, has matured into a quantum technology that can harness this strange behaviour for technological applications with far-reaching consequences, which uses quantum bits (qubits) for information processing. Experiments suggest that photons are the most successful candidates for realising qubits, which indicates that integrated photonic platforms will play a crucial role in realising quantum technology. This paper surveys the various photonic platforms based on different materials for quantum information processing. The future of this technology depends on the successful materials that can be used to universally realise quantum devices, similar to silicon, which shaped the industry towards the end of the last century. Though a prediction is implausible at this point, we provide an overview of the current status of research on the platforms based on various materials.

quant-ph↗