Properties of unstable resonators with field rotation. I. Theoretical principles

Abstract

Laser micromachining is a powerful technique that is commonly used in microfabrication. Typically such laser systems are computer controlled, and the required microstructure is fabricated by multiple machining iterations, where the control program is modified until the required structure is achieved. Here a simple method of simulating an approximation of the surface topography that will result from a computer numerically controlled (CNC) laser machining program is presented for glass and silicon. The simulation allows rapid prediction of the etch depths, workpiece contours, resulting structuring and machining artifacts. It was found that the simulated surface topology closely matched that of the structures machined in each material (4% of the maximum etch depth for borosilicate, 7% for sodalime and 9% for silicon). A non-planar microfluidic channel system with through-substrate ports was produced in both types of glass and silicon. The design took 12 min to simulate and 74 min to machine, and the simulation was accurate to within 4 μm of the machined glass substrate.

Investigation of UR90 outputting annular beam for a chemical oxygen-iodine laser

“…To ensure that the rectangle beam emerges itself while oscillating, the geometric beam size is established proper ratio between the length of the beam and the width. The proportion is expressed as follow: 1 =(M2 +M4)a;h =(M +M3 )a;l/h =M (2) Which is equal to the optical magnification. For the COIL, as the length of the gain medium along the gas flow is defmite, in case of lower gain, the magnification is selected lower, the shape of the beam is close to square and the volume of the mode is lager.…”

<title>Vector eigenmodes in a cylindrical laser</title>

“…1); the compact leg with mode rotation, the waxicon, the annular leg, the rear cone, the reflaxicon, and the coatings. As a result of the effect from the coatings on the annular elements, the azimuthal Fourier coefficients transform for the reflection from the first surface according to (6) [b(r)ei2 a(r) jf(r)) where a(r)= Rr(r)±R. (r) b(r) = Rr(r)-R+(r) (7) For two successive reflections, the a(r) and b(r) become functions of two variables, r1 and r2.…”

Negative branch hybrid resonator for COIL

“…A conventional unstable resonator with concentric resonator mirrors 1 is not very practical because the outcoupling ring width becomes very small compared to its diameter. Other, more complicated resonator configurations have been worked out and tested with COIL, like resonators with beam rotation [2][3][4] . Some of them have been shown to produce a good beam quality and alignment insensitivity.…”