Plane-parallel plates as laser reflections

The problem of the reflectivity of complex reflecting systems in laser devices is investigated. Specific attention is given to plane-parallel plates acting as laser reflectors.The authors are grateful to B. A. Sotskii, A. M. Goncharenko, and F. I. Fedorov for their useful comments.     

A laser with a passive Q switch

A phototropic KS-19 glass switch is considered. It is shown that interference effects cause reflections from the ends of the rod and the faces ot the switch to reduce the pulse energy. The effect is suppressed by bringing the shutter into optical contact with the rod. The advantages are discussed.     

Anomalous small-angle scattering as a way to solve the Babinet principle problem

X-ray absorption spectra (XAS) have been used to determine the absorption edges of atoms present in a sample under study. A series of small-angle X-ray scattering (SAXS) measurements using different monochromatic X-ray beams at different wavelengths near the absorption edges is performed to solve the Babinet principle problem. The sizes of clusters containing atoms determined by the method of XAS were defined in SAXS experiments. In contrast to differential X-ray porosimetry, anomalous SAXS makes it possible to determine sizes of clusters of different atomic compositions.