Mitigation of carrier induced optical bistability in silicon ring resonators

TL;DR

This paper investigates how free carriers and thermal effects cause spectral distortion in silicon microring modulators and proposes mitigation strategies to improve device performance for optical signal processing.

Contribution

It provides a detailed analysis of spectral distortion mechanisms and introduces mitigation techniques such as biasing and small-signal drive to enhance silicon ring modulator functionality.

Findings

Two-photon nonlinearity can be mitigated by optimal biasing.

Spectral distortion can be restored with small-signal drive.

Operating conditions significantly affect device performance.

Abstract

We present a detailed study of electrical and optical generated free carrier on the spectral characteristics of a silicon microring modulator. The spectral distortion generated due to thermal and free carriers is presented, and the mechanism for mitigation is also presented. We observed that two-photon induced nonlinearity could be addressed by operating the modulator at suitable bias points. Furthermore, by applying small-signal drive the spectral distortion can be restored. We also present the effect of optical power and drive signal limit on the spectral characteristics. The study allows one to identify suitable device performance and operating conditions to utilize silicon ring modulator for optical signal processing.