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 (M 2 ∼ 5) 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 (M 2 ≤ 1.1). With single-end pumping, laser power of 4.7 W (M 2 ∼ 1.3) 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 >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.

A Review of Progress about Birefringent Filter Design and Application in Ti:sapphire Laser

“…In 2011, Demirbas presented a tunable femtosecond Cr:colquiriite laser, which concluded a quartz BRF with a thickness of 7.3 mm in the cavity [60]. However, with the discovery and wide use of a solid broadband gain medium in all-solid-state tunable lasers [61][62][63], the careful and comprehensive optimization of the BRF becomes a necessary and key work. In 2017, U. Demirbas once presented detailed design considerations of off-axis BRF [64].…”

375-400nm UV Generation via an Alexandrite Laser and Zn-Indiffused MgO-Doped PPLN Waveguides

“…The work presented here looks at combining rapid progress in two areas of laser development for addressing these applications. Diodepumped Alexandrite lasers have become a low-cost and simple approach to achieving multi-watt powers in the near-infrared at around 720-800nm [1]. Zn-indiffused MgO-doped PPLN waveguides have recently demonstrated impressive second harmonic generation (SHG) conversion efficiencies in the near-infrared [2] as well as conversion into the UV with doubling to 390nm recently reported [3].…”

High Power Alexandrite Laser for Tunable UV-Blue Generation

“…Diodepumped solid-state lasers provide excellent mode quality, linewidth and stability but with limited direct emission in the UV-blue region. Red-diode-pumped Alexandrite lasers have undergone rapid development recently with compact systems achieving multi-watt TEM00 operation [1]. Their broad emission at 720-800nm matches the UVblue region via second-harmonic-generation (SHG).…”