Optimizing Photonic Nanostructures via Multi-fidelity Gaussian Processes

We apply numerical methods in combination with finite-difference-time-domain (FDTD) simulations to optimize transmission properties of plasmonic mirror color filters using a multi-objective figure of merit over a five-dimensional parameter space by utilizing novel multi-fidelity Gaussian processes approach. We compare these results with conventional derivative-free global search algorithms, such as (single-fidelity) Gaussian Processes optimization scheme, and Particle Swarm Optimization---a commonly used method in nanophotonics community, which is implemented in Lumerical commercial photonics software. We demonstrate the performance of various numerical optimization approaches on several pre-collected real-world datasets and show that by properly trading off expensive information sources with cheap simulations, one can more effectively optimize the transmission properties with a fixed budget.Comment: NIPS 2018 Workshop on Machine Learning for Molecules and Materials. arXiv admin note: substantial text overlap with arXiv:1811.0075

Optimizing Photonic Nanostructures via Multi-fidelity Gaussian Processes

We apply numerical methods in combination with finite-difference-time-domain (FDTD) simulations to optimize transmission properties of plasmonic mirror color filters using a multi-objective figure of merit over a five-dimensional parameter space by utilizing novel multi-fidelity Gaussian processes approach. We compare these results with conventional derivative-free global search algorithms, such as (single-fidelity) Gaussian Processes optimization scheme, and Particle Swarm Optimization---a commonly used method in nanophotonics community, which is implemented in Lumerical commercial photonics software. We demonstrate the performance of various numerical optimization approaches on several pre-collected real-world datasets and show that by properly trading off expensive information sources with cheap simulations, one can more effectively optimize the transmission properties with a fixed budget

General-purpose Information-theoretical Bayesian Optimisation:A thesis by acronyms

Bayesian optimisation (BO) is an increasingly popular strategy for optimising functions with substantial query costs. By sequentially focusing evaluation resources into promising areas of the search space, BO is able to find reasonable solutions within heavily restricted evaluation budgets. Consequently, BO has become the de-facto approach for fine-tuning the hyper-parameters of machine learning models and has had numerous successful applications in industry and across the experimental sciences.This thesis seeks to increase the scope of information-theoretic BO, a popular class of search strategies that regularly achieves state-of-the-art optimisation. Unfortunately,current information-theoretic BO routines require sophisticated approximation schemes that incur substantially large computational overheads and are, therefore, applicable only to optimisation problems defined over low-dimensional and Euclidean search spaces. This thesis proposes information-theoretic approximations that extend theMax-value Entropy Search of Wang and Jegelka (2017) to a much wider class of optimisation tasks, including noisy, batch and multi-fidelity optimisation across both Euclidean and highly-structured discrete spaces. To comprehensively test our proposed search strategies, we construct novel frameworks for performing BO over the highly-structured string spaces that arise in synthetic gene design and molecular search problems, as well as for objective functions with controllable observation noise. Finally,we demonstrate the real-world applicability of BO as part of a sophisticated machine learning pipeline for fine-tuning multi-speaker text-to-speech models