Input Mirror Research Articles

Stratospheric measurements of H2O and the diurnal change of NO and NO2

WE have flown a radiometer from a balloon (a detailed description of which will be published elsewhere), which senses infrared emission from minor stratospheric constituents on the atmospheric limb. To provide a vertical profile of their concentration, the input mirror of the radiometer scans between 7° below and 2° above the horizontal, as illustrated in Fig. 1. The vertical field of view is 0.4°. Every 5.5 min the same mirror scans to an internal black body and to a space view at 18° upwards, thereby providing a two-point calibration.

Locking of transverse modes in a Raman laser

A theoretical analysis is made of the characteristic features of the excitation of the stimulated Raman scattering by a monochromatic beam in a plane-parallel optical resonator. It is shown that in this case the transverse Stokes modes are locked. The nature of the locking is governed, generally speaking, by the amplitude-phase distribution of the pumping radiation over the input mirror of the resonator and not by the intensity of this radiation. The possibility of generation of a single transverse amplitude-phase distribution of the pumping radiation field is considered. The examples of two- and three-mode resonators are used to illustrate the method for finding the distribution of the pumping field necessary for the excitation of a single transverse Stokes mode.