Abstract
Recently, a new class of laser resonators was introduced that utilizes diffractive mirrors and an additional intracavity diffractive phase element. High modal discrimination and low fundamental-mode loss were achieved simultaneously by use of sinusoidal and pseudorandom diffractive phase elements. An intracavity phase element consisting of a simple single-step phase modulation is approximated by a Gaussian with a small radius. Explicit expressions are obtained for the modal-discrimination factor as a function of resonator parameters with a Gaussian output mirror. Numerical simulations are performed for a phase element with a step singularity in the phase function, the fundamental mode of this cavity being super-Gaussian. The modal discrimination of the cavity is studied for different radii of the single-step phase modulation, the position of the phase plate, and the cavity Fresnel number. Optimum solutions are found for a plane output mirror with either a striped or a circular shape.
Original language | English (US) |
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Pages (from-to) | 3025-3029 |
Number of pages | 5 |
Journal | Applied Optics |
Volume | 38 |
Issue number | 14 |
DOIs | |
State | Published - May 10 1999 |