Transfer printing micro-assembly of silicon photonic crystal cavity arrays: beating the fabrication tolerance limit

TL;DR

This paper presents a transfer printing technique for silicon photonic crystal cavity arrays that overcomes fabrication tolerances, enabling the assembly of ordered, wavelength-sorted arrays with high precision and dynamic response measurement.

Contribution

The authors introduce a releasable pixel approach for PhCCs that allows overcoming fabrication variability through micro-assembly, with high-throughput measurement and sorting capabilities.

Findings

Successfully transferred and sorted 119 PhCCs in one session.

Demonstrated in-situ measurement of device response during transfer.

Revealed plastic and elastic effects in device response over time.

Abstract

Photonic crystal cavities (PhCCs) can confine optical fields in ultra-small volumes, enabling efficient light-matter interactions for quantum and non-linear optics, sensing and all-optical signal processing. The inherent nanometric tolerances of micro-fabrication platforms can induce cavity resonant wavelength shifts two-orders of magnitude larger than cavity linewidths, prohibiting fabrication of arrays of nominally identical devices. We address this device variability by fabricating PhCCs as releasable pixels that can be transferred from their native substrate to a receiver where ordered micro-assembly can overcome the inherent fabrication variance. We demonstrate the measurement, binning and transfer of 119 PhCCs in a single session, producing spatially ordered arrays of PhCCs, sorted by resonant wavelength. Furthermore, the rapid in-situ measurement of the devices enables measurements of the PhCCs dynamic response to the print process for the first time, showing plastic and elastic effects in the seconds to hours range.