Multiscale Phase Retrieval

TL;DR

This paper introduces advanced phase retrieval strategies that approach quantum-limited performance for large-scale coherent field imaging, potentially enabling lensless, large aperture laser imaging using integrated photonic devices.

Contribution

It presents novel phase retrieval methods utilizing group testing with interferometer networks, overcoming previous large-scale implementation challenges.

Findings

Strategies approach quantum-limited estimation for >1 megapixel fields

Use of interferometer networks for efficient phase retrieval

Potential for lensless, large aperture imaging with integrated devices

Abstract

While characterization of coherent wavefields is essential to laser, x-ray and electron imaging, sensors measure the squared magnitude of the field, rather than the field itself. Holography or phase retrieval must be used to characterize the field. The need for a reference severely restricts the utility of holography. Phase retrieval, in contrast, is theoretically consistent with sensors that directly measure coherent or partially coherent fields with no prior assumptions. Unfortunately, phase retrieval has not yet been successfully implemented for large-scale fields. Here we show that both holography and phase retrieval are capable of quantum-limited coherent signal estimation and we describe phase retrieval strategies that approach the quantum limit for >1 megapixel fields. These strategies rely on group testing using networks of interferometers, such as might be constructed using emerging integrated photonic, plasmonic and/or metamaterial devices. Phase-sensitive sensor planes using such devices could eliminate the need both for lenses and reference signals, creating a path to large aperture diffraction limited laser imaging.