Demonstration of 3-port grating phase relations

TL;DR

This paper experimentally verifies the phase relations of 3-port gratings by using coupled Fabry-Perot cavities with specially designed gratings, confirming theoretical predictions about their phase behavior.

Contribution

It provides the first experimental validation of theoretical phase relations in 3-port gratings using fabricated gratings with different diffraction efficiencies.

Findings

Validated theoretical phase relations for 3-port gratings

Demonstrated use of gratings as couplers in Fabry-Perot cavities

Compared gratings with different second-order diffraction efficiencies

Abstract

We experimentally demonstrate the phase relations of 3-port gratings by investigating 3-port coupled Fabry-Perot cavities. Two different gratings which have the same 1st order diffraction efficiency but differ substantially in their 2nd order diffraction efficiency have been designed and manufactured. Using the gratings as couplers to Fabry-Perot cavities we could validate the results of an earlier theoretical description of the phases at a three port grating.