A photon absorber minimizes the mixing of unwanted reflected electromagnetic waves with the main clockwise and counter-clockwise propagating electromagnetic waves of a ring laser gyroscope. A round hole in the middle of the absorber allows the main waves to pass and an angulated front surface deflects reflected waves away from the main waves. Most of the reflected waves which impinge on the photon absorber are absorbed. A photon absorber is fabricated from light absorbing filter glass with anti-...

A vehicle window includes a glass ply with a layer of thermoset polyurethane over the outer face of the glass which inhibits Restrahlen Band reflection at 8-12 microns from the glass. The polyurethane layer may include an inner layer portion of relatively hard polyurethane and an outer layer of relatively soft polyurethane.

A focus sensing system adaptable for use in microscopes or other optical systems incorporates a selective beam block. An outgoing reference beam, incident upon a target to be inspected, is reflected to become an incoming reference beam. A beam block inserted within the optical system selectively rejects unwanted reflections from surfaces other than the target allowing the desired incoming reference beam to be photodetected without interference from reflections off of surfaces that are not of int...

An optical filter is provided for suppressing unwanted reflections of background light when used with a display device such as a cathode ray tube or an electroluminescent screen, or in optical communication or surveillance. The filter has multiple thin layers including a first series of layers for suppressing reflections from its outer surface and a second series of layers constituting a bandpass interference filter. The first series of layers is arranged to suppress reflections over a broad wav...

The invention relates to a photography aid, and in particular to a photography aid for use with microscopes, such as stereo microscopes. The photography aid includes a reservoir adapted to contain a fluid and a holding dish. An opening is disposed between the reservoir and the holding dish and adapted to permit the fluid to pass between the reservoir and the holding dish. An object can then be placed in the holding dish and photographed.

Improved performance in a fiber interferometer gyro results from eliminat signals attributed to unwanted reflections from the fiber ends and the coupling lenses. A coiled single-mode fiber bidirectionally transmits beams radiating from a continuous wave laser to a detector. A fixed frequency oscillator amplitude modulates the laser output and provides a reference signal at the same frequency to enable synchronous detection of the detector output signals. Shifting the reference signal .pi./2 radi...

A system for distinguishing real target reflections from ghost target reflections for use in adjusting the orientation of a plane defined by a rotating laser beam from a laser transmitter is provided. One or more retroreflective targets are positioned in desired locations along a rotational arc to define the desired plane through which the laser beam is rotated. The laser beam rotates back and forth scanning for targets positioned along the rotational arc. The laser beam is reflected from the ta...

A shellcase body for use as part of an ammunition cartridge, which includes a base portion at one end, a middle portion having a substantially straight sidewall and joined with the base portion, and a shoulder portion joined to and extending from the middle portion. A neck portion may be joined to and extend from the shoulder portion. The shoulder portion is typically annularly shaped and includes a semi-circular sidewall that extends between an aft end and a fore end. The semi-circular sidewall...

The shape of a reflecting surface within an elastic-wave transmitting medium is determined by an adaptation of holography, by propagating through the medium from a source or source pattern coherent elastic waves that are scattered and reflected by the surface to an areal detector array, the outputs of which combined with a reference wave are recorded as an optical hologram. Reconstructions from the hologram show not only the reflecting surface but a virtual source or source pattern image due to ...

An optical package arrangement is disclosed which is capable of reducing internal reflections while maintaining a common axis between the input device (for example, a laser diode) the output device (for example, an optical fiber) and various elements interposed therebetween. The output device is designed to include a bevel angle (.beta.) for redirecting reflections away from the common axis. In accordance with the teachings of the invention, an optical element (for example, an isolator, filter, ...