Actively coupled optical waveguides

TL;DR

This paper investigates a pair of nonlinear optical waveguides with active gain and absorption, demonstrating their ability to exhibit stable regimes and function as sensitive power comparators due to active coupling effects.

Contribution

It introduces a novel active coupling mechanism in optical waveguides that enables stable and oscillatory regimes, and shows their potential as sensitive power comparators.

Findings

Stable stationary and oscillatory regimes observed across gain-loss ratios.

Active coupling enables the waveguides to act as sensitive power comparators.

The structure can detect tiny differences in input powers effectively.

Abstract

We consider light propagation through a pair of nonlinear optical waveguides with absorption, placed in a medium with power gain. The active medium boosts the in-phase component of the overlapping evanescent fields of the guides, while the nonlinearity of the guides couples it to the damped out-of-phase component creating a feedback loop. As a result, the structure exhibits stable stationary and oscillatory regimes in a wide range of gain-loss ratios. We show that the pair of actively-coupled ($\mathcal{AC}$) waveguides can act as a stationary or integrate-and-fire comparator sensitive to tiny differences in their input powers.