Intensity noise self-regulated solid-state laser at 1.5${\mu}$m using an ASHG based Buffer Reservoir

TL;DR

This paper demonstrates a novel intensity noise self-regulation method in a 1.5μm solid-state laser using an ASHG-based buffer reservoir, significantly reducing noise at relaxation oscillation and GHz resonances.

Contribution

It introduces an innovative use of second-harmonic generation as a buffer reservoir to suppress intensity noise in a telecom-wavelength laser.

Findings

35 dB reduction of intensity noise at relaxation oscillation frequency

Effective cancellation of amplified spontaneous emission beating

Implementation of ASHG as a noise control mechanism

Abstract

An absorption mechanism based on second-harmonic generation (ASHG) is successfully implemented as a buffer reservoir in a solid-state Er,Yb:Glass laser emitting at telecom wavelength. We show that a slight ASHG rate conversion of 0.016% using a BBO crystal enables to cancel out the excess intensity noise at the relaxation oscillation frequency, i.e. 35 dB reduction, as well as to cancel the amplified spontaneous emission beating at the free spectral range resonances of the laser lying in the GHz range.