Single-mode selection using coherent imaging within a slab waveguide CO2 laser

Abstract

A technique for selecting a single high-order lateral mode of a rf excited slab waveguide laser is described. An in-cavity grid which matches the periodicity of the desired mode, together with slab waveguide dimensions which create coherent imaging by the Talbot effect, have produced a stable output power of 155 W in a high spectral purity, single-resonator mode.

Discontinuous phase elements for transverse mode selection in laser resonators

“…Finally, we compared the performance of our DPE with that of absorbing wires of various thicknesses. 2 The maximal single mode TEM 01 power of the CO 2 laser, obtained for a wire diameter of 75 m, was 20% lower than with the DPE, confirming the advantage of our approach.…”

Laguerre-Gaussian modes selection in diode-pumped solid-state lasers

“…Several transverse HG and LG modes were selected in He-Ne gas lasers, 4,5) and then higher order modes were investigated in other types of gas, solid-state and semiconductor lasers. [7][8][9][10][11][12][13][14][15][16][17][18] Generally, intra-cavity elements for mode selection are introduced in the laser resonator in order to produce low losses for a specific desired mode and high losses for other modes. Mode selection techniques based on the usage of intra-cavity apertures, phase plates, gradient mirrors and on different resonator configurations were reviewed by Oron et al 19) The number of reports on mode selection in solid-state lasers has dramatically increased during the last two decades with the advent of diode-laser pumped solid-state lasers (DPSSLs).…”

Exciting higher-order radial Laguerre–Gaussian modes in a diode-pumped solid-state laser resonator

“…This in turn increases the mode order within the cavity and for the selection of a desired mode, methods including pump-shaping [20], intracavity beam shaping [21][22][23][24], and even Talbot imaging of periodic obstacles [25] may be employed. An alternative approach is to consider how to select a particular high-order mode for maximizing power extraction and then consider outside the cavity approaches to improve the beam quality factor of such modes.…”