Laser Stabilisation Using a Slow Light Cavity

Abstract: In this thesis the application of slow light effects to the area of laser stabilisation is investigated. The frequency stability of lasers locked to external cavities is limited by the stability of the modes in the reference cavity. By using dispersive slow light effects the effective length of a cavity can be increased by several orders of magnitude, without a proportional increase in the sensitivity to fluctuations in cavity length, thereby yielding a net increase in stability. The effects are achieved through spectral hole burning in cryogenically cooled rare-earth ion doped crystals. Two sets of experiments are carried out, the first focusing on hole burning and the second focusing laser locking. Linewidths and frequency drift of the cavity spectrum are studied. Feedback control using an error signal generated from the slow light cavity is demonstrated, but successfully locking the laser is still yet to be achieved.