Abstract: A laser output radiation with reduced energy noise components is produced which is also usable for the formation of short, stable laser pulses in the pico- and sub-picosecond ranges. The low noise components are obtained by superposition of the resonator wave in the active medium with its fed back output radiation lying on the order of magnitude of the spontaneous radiation emission of the oscillating resonator wave.

Abstract: A laser for the production and radiation of monochromatic light to a first polarizer arranged in the beam path of a resonator of the laser and operative to pass one of two light beam components linearly polarized perpendicularly to one another and to deflect the other linearly polarized component out of the resonator onto a photodetector for detecting that reflected part of the radiated light. A second polarizer is arranged in the direction of radiation of the light beam, behind a decoupling mirror of the resonator, and is operative to convert linearly-polarized light into circularly-polarized light. Adjacent the second polarizer in the direction of radiation is a collimator consisting of an optical system for widening the transmission beam to a remote reflector and narrowing the reflected beam received from the remote reflector back into the second polarizer and the resonator from which it is deviated onto the photodetector.

Abstract: A method is provided for impregnating a water-sensitive solid containing micropores, being substantially free of pores having a diameter above 1000 A., and comprising at least one metal oxide with a water-soluble material, said micropores containing a substantially water-insoluble gas, which comprises:1. replacing the water-insoluble gas in said micropores with a hydrophylic gas selected from the group consisting of steam, substantially water-soluble gases, and mixtures thereof by stripping said solid with said hydrophylic gas; and2. impregnating said solid by immersing the stripped solid in an agueous solution of said material.