Abstract: A non-retro angle of arrival meter in which reflection means are mounted ative to an aperture and to detectors for radiation such that radiation passing through the aperture is reflected from the reflection means to the detectors to cause signals to be produced at the detectors that can be processed by a processor for recording these signals and determining the direction from which the radiation is originating.

Abstract: Apparatus for instantaneously measuring the horizontal and vertical aspect ngles of radiation received from a remote laser transmitter. A triangular corner reflector serves as the receiver of radiation and detectors are provided along the three edges of the reflector. From the number of detectors activated on each side of the reflector, the direction of radiation from UV to millimeter wave length is determined.

Abstract: An output coupler, for laser cavities with totally reflecting mirrors, hag a beam splitter and a mirror mounted so that the direction of the output beam of the laser is invariant to changes in the output coupling coefficients. The percentage of the laser's energy which is coupled out into an external beam can be continuously varied or varied to obtain the optimum output coupling coefficient and then left set on this value. This device can also be used as a variable beam splitter with an invariant direction for the reflected beam when used external to the cavity of any laser.

Abstract: An instrument (reflectometer) for continuously measuring the reflectance perties of materials as a function of the angle of incidence in which a sample and a mirror are mounted on a rotating platform in such a manner that, as the angle of incidence on the sample is varied, the reflected radiation is always incident on a detector which is fixed with respect to the rotating platform. The angle of incidence on the sample is measured and used to drive an axis of an X-Y recorder. The angle of incidence on the mirror is measured and used to correct the detected signal for any errors introduced by the properties of the mirror. This corrected signal is then used to drive the other axis of the X-Y recorder to produce a plot of the reflection coefficients vs angle of incidence for the sample. For fixed angles of incidence on the sample the detector can be moved to produce a plot of the diffused reflections as a function of the angular deviation from the specular angle.