High-power 7.4W TEM₀₀ and wavelength-tunable alexandrite laser with a novel cavity design and efficient fibre-coupled diode-pumping

Abstract

We report significant improvement in the performance of TEM 00 alexandrite laser operation by employing high power fibre-coupled red diode pumping, novel cavity design, and active direct Shack-Hartmann wavefront sensor measurement of pump-induced lensing. We demonstrate 12.7 W of laser power in low-order ( <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"> <mml:msup> <mml:mi>M</mml:mi> <mml:mn>2</mml:mn> </mml:msup> <mml:mo>∼</mml:mo> <mml:mn>5</mml:mn> </mml:math> ) mode operation from a compact double-end-pumped cavity, and with novel cavity design, a record power of 7.4 W in TEM 00 operation with excellent beam quality ( <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"> <mml:msup> <mml:mi>M</mml:mi> <mml:mn>2</mml:mn> </mml:msup> <mml:mo>≤</mml:mo> <mml:mn>1.1</mml:mn> </mml:math> ). With single-end pumping, laser power of 4.7 W ( <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"> <mml:msup> <mml:mi>M</mml:mi> <mml:mn>2</mml:mn> </mml:msup> <mml:mo>∼</mml:mo> <mml:mn>1.3</mml:mn> </mml:math> ) was achieved with slope efficiencies as high as 54.9 %; a record efficiency for red-diode-pumped alexandrite. Using a birefringent filter, continuous laser wavelength tuning from 725-808 nm is achieved in diffraction-limited TEM 00 mode, with laser power of 4.7 W at 765 nm, and &gt;1 W across 730-805 nm, which is a higher tunable power than any other directly diode-pumped vibronic laser, to the best of our knowledge.

Topics & Concepts