Effect of pump beam resonator on the performance of narrow line-width Rhodamine 110 dye laser

Abstract

This paper presents a study on the effect of pump beam resonator on the performance of Rhodamine 110 dye laser. The pump beams were from copper vapor laser (CVL) with different resonators such as plane–plane and an unstable resonator of same average power of 5.0W. For a particular pump beam, the dye laser beam power, line-width, divergence, pulse shape and dye gain medium size were measured. The dye laser wavelength stability and pointing stability were also studied for both the pump beams. It is shown that the dye laser beam properties significantly depend on the pump laser resonator configuration. The unstable resonator CVL pumped dye laser produced better line-width (3.6GHz vs 6GHz), divergence (9mrad vs 16mrad) and power (510mW vs 410mW) as compared to that pumped with plane–plane resonator CVL. These differences are attributed to larger pump beam flux and consequently larger dye gain medium size characteristics for unstable resonator CVL pump beam due to its better divergence characteristics as compared to plane–plane resonator CVL. Better wavelength stability of dye laser obtained from unstable resonator CVL pump beam was explained due to its better pointing stability as compared to plane–plane resonator pump beam.