Relaxation oscillations, stability, and cavity feedback in a superradiant Raman laser.
We experimentally study the relaxation oscillations and amplitude stability properties of an optical laser operating deep into the bad-cavity regime using a laser-cooled ^{87}Rb Raman laser. By combining measurements of the laser light field with nondemolition measurements of the atomic populations, we infer the response of the gain medium represented by a collective atomic Bloch vector. The results are qualitatively explained with a simple model. Measurements and theory are extended to include the effect of intermediate repumping states on the closed-loop stability of the oscillator and the role of cavity feedback on stabilizing or enhancing relaxation oscillations. This experimental study of the stability of an optical laser operating deep into the bad-cavity regime will guide future development of superradiant lasers with ultranarrow linewidths.
JILA, NIST and Department of Physics, University of Colorado, Boulder, Colorado 80309-0440, USA.
Justin G
JG
Bohnet
Zilong
Z
Chen
Joshua M
JM
Weiner
Kevin C
KC
Cox
James K
JK
Thompson