Lateral displacement of the mode axis in a misaligned Porro prism resonator.
The lateral shift of the mode axis in a misaligned Porro prism resonator is analyzed. A method to find the tilted mode axis in a misaligned Porro prism resonator is introduced. Expressions for the displacement of the mode axis are deduced. They predict that the lateral displacement of the mode axis is proportional to the horizontal misalignment angle beta and highly dependent of the prism azimuth angle theta. Experimental results obtained agree well with theory.
Method of calculating the alignment tolerance of a Porro prism resonator.
A method of calculating the angular alignment tolerance of a Porro prism laser oscillator is presented. The reduction in mode volume due to misalignment is found by a ray optical approach. An analytical expression for alignment tolerance, in terms of resonator length L, prism azimuth angle theta, rod location L(2), and rod aperture radius alpha is obtained. An experiment was set up to measure the laser output reduction due to reflector tilting. Results obtained are in good agreement with the theoretical predictions.
A lossless, passive isolator for optically pumped far‐infrared lasers
A lossless, passive technique which isolates the pump and the far‐infrared cavities in an optically pumped far‐infrared laser system has been applied successfully. The isolator consists of a polarizer and a quarter‐wave plate. Pumping is accomplished with a circularly polarized beam, and the resulting circular polarization of the far‐infrared output stability without sacrifice of either power or mode quality.