Novel laser resonators

We are interested in general transverse mode selecting methods inside laser resonators by the use of appropriate optics that alter the amplitude or the phase of the light. Using amplitude masks we explained the creation of petal-like modes in Porro prism resonators, and designed a Fourier transforming resonator for the creation of Bessel-Gauss beams. Intra-cavity diffractive optical elements may be used to adjust the phase of the oscillating mode to select a desired transverse intensity profile. We make use of such optics to study flat-top beam generation inside cavities, but in principle this technique may be used for the creation of any transverse mode. An important research question in all the above cases is the competition one might expect between the desired transverse mode and the other possible modes, as this influences the output of the resonator. It is possible to adjust in real time this competition by using a combination of dynamic and static optical elements inside the cavity. We are interested in designing resonators with special modes that will extract maximum energy from the cavity, but with minimal thermal aberrations.

This work has relevance to the design of high-brightness solid state lasers, where high energy in a good beam quality is required, as well as in the generation of high-power flat-top beams for direct use in materials processing.

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