Ultrafast perturbation maps as a quantitative tool for testing of multi-port photonic devices

TL;DR

This paper introduces a rigorous, quantitative method based on Lorentz reciprocity for ultrafast photomodulation mapping, enabling accurate, non-contact testing and optimization of multi-port photonic devices at wafer scale.

Contribution

It develops a general, computationally efficient approach to predict transmittance perturbation maps for arbitrary linear photonic systems, validated by experimental results.

Findings

High accuracy in predicting perturbation maps

Excellent agreement between simulations and experiments

Potential for device testing and design optimization

Abstract

Advanced photonic probing techniques are of great importance for the development of non-contact wafer-scale testing of photonic chips. Ultrafast photomodulation has been identified as a powerful new tool capable of remotely mapping photonic devices through a scanning perturbation. Here, we develop photomodulation maps into a quantitative technique through a general and rigorous method based on Lorentz reciprocity that allows the prediction of transmittance perturbation maps for arbitrary linear photonic systems with great accuracy and minimal computational cost. Excellent agreement is obtained between predicted and experimental maps of various optical multimode-interference devices, thereby allowing direct comparison of a device under test with a physical model of an ideal design structure. In addition to constituting a promising route for optical testing in photonics manufacturing, ultrafast perturbation mapping may be used for design optimization of photonic structures with reconfigurable functionalities.