Near-infrared light amplification in a photorefractive ring resonator

Summary form only given. Unidirectional ring resonators have unique photorefractive features. For example, their geometry is often very tolerant to misalignment, as the gratings that develop are self-adaptive, and can grow from scattered light. The oscillating light shows interesting pattern dynamics and coherence effects. We successfully demonstrated ring resonators at 830 nm and 1064 nm wavelengths. This is the first report, to our knowledge, of a photorefractive ring resonator working at wavelengths above I gm and achieving an oscillating power that exceeds the incident pump power. Its previous realizations were in the regimes where absorption was high and therefore no net amplification was observed. The experimental configuration consisted of three mirrors and a photorefractive crystal, Rh:BaTiO/sub 3/, pumped by a CW near-infrared, single-longitudinal-mode laser.