Intracavity Brillouin gain characterization based on cavity ringdown spectroscopy

Abstract

We report a technique based upon the cavity ringdown method that enables to characterize the Brillouin gain coefficient directly in a laser cavity. Material gain, optical cavity parameters and lasing properties can be extracted from measurements whithin a single experiment.

Cavity Ring-Down Spectroscopy: Recent Technological Advancements, Techniques, and Applications

“…The fiber as well as the couplers contributes toward various losses such as the fiber’s transmission loss, insertion, and coupling losses, etc., which can significantly reduce the inherent ring-down time of the resonator. To recompense these losses, amplifiers such as erbium-doped fiber amplifiers (EDFA) are utilized, which provide a gain for maintaining the signal strength. , The sensing region is usually composed of a normal or tapered fiber but might consist of other components such as a gas cell, FBG, or a variable attenuator . Flexibility of incorporating different sensor elements is also one of the major advantages of fiber-based CRDS techniques.…”

“…To recompense these losses, amplifiers such as erbium-doped fiber amplifiers (EDFA) are utilized, which provide a gain for maintaining the signal strength. 40,43 The sensing region is usually composed of a normal or tapered fiber 39 but might consist of other components such as a gas cell, 44 FBG, 41 or a variable attenuator. 45 Flexibility of incorporating different sensor elements is also one of the major advantages of fiberbased CRDS techniques.…”

“…An interesting recent study 43 reported the measurement of Brillouin gain by examining the simultaneous Brillouin scattering (SBS) from a pump laser at 1550 nm, propagating in a fiber. The fiber resonator allowed multiple circulations of the Stokes wave from SBS, which was further probed by a tunable probe laser.…”