title: Unidirectional single-frequency operation of a Nd:YVO4 ring laser with and without a Faraday element.
abstract: We demonstrate high-performance unidirectional and single-frequency ring-laser operation based on a diode-side-pumped Nd:YVO4 bounce amplifier, obtained in a ring system both with and without a Faraday rotating element. Ring-laser operation with intracavity Faraday unidirectional element produces 15-W cw output in a TEM00 and single-longitudinal mode with beam propagation parameter M2 < 1.1 with 35-W diode pumping. A novel non-Faraday-based ring laser uses a polarization-dependent output coupler and asymmetric polarization state in the birefringent Nd:YVO4 gain medium and is demonstrated to produce highly unidirectional (1200:1) single-frequency output of 14 W in a TEM00 mode with beam propagation factor M2 < 1.2 at 30 W of diode pumping.
authors.affiliation: Blackett Laboratory, Imperial College, London SW7 2BW, United Kingdom. b.thompson@ic.ac.uk
authors.forename: Benjamin A
authors.initials: BA
authors.lastname: Thompson
authors.forename: Ara
authors.initials: A
authors.lastname: Minassian
authors.forename: Michael J
authors.initials: MJ
authors.lastname: Damzen