An electronically tuneable light source includes a source (10) of white light, an acousto-optic modulator (16) which includes a transparent medium and means (17) for generating an acoustical wave in the medium, and means for directing the collimated beam of the white light onto the medium at a preselected angle θ/2 to a line which is perpendicular to the direction of travel of the acoustical wave. Interaction of the light beam with the acoustical wave causes diffraction of the light beam. Means (22) are provided for selecting a visible band of the diffracted beam at an angle to the incident collimated beam of light equal to approximately 8.

Electronically tuneable light source

A device for detecting fraudulent negotiable instruments by coating areas of the negotiable instruments with a fluorescent substance that, when subjected to an ultraviolet light source, develops an emission of a certain known frequency. The device includes a filter which only passes known emission frequencies so that negotiable instruments can be rejected that do not exhibit that frequency.

Negotiable instrument fraud detector and processor

An improved automated acousto-optic analyzer system includes an acousto-optic tunable filter which is coupled with a source of radiation to produce pulsed light at predetermined wavelengths. This light is transmitted through a gas stack containing gases to be analyzed, to a distant detector. The configuration of the acousto-optic tunable filter, radiation source on one side of an environment of interest and a detector on the opposite side of an environment of interest produces spatial separation of the tuned, diffracted light from the undiffracted broad spectrum of the light source at the detector. This configuration eliminates the need for polarizers in the system. It also combines the tuning function of the AOTF with a chopping function, allowing extraneous radiation to be discriminated against. Thus the improved configuration of the disclosed invention permits effective operation of the gas analysis system in a gas stack characterized by extremely high ambient temperatures.

Automated acousto-optic infra-red analyzer system for monitoring stack emissions

The invention relates to a method and device for controlling the amplitude of the wavelength spectrum of ultra-short light pulses emitted by multipass laser amplifiers. According to the invention, a programmable acousto-optic device (8) is introduced into a laser cavity of a multipass amplifier (10), in order to modify slightly the amplitude of the spectrum of the light pulse with each passage, owing to a collinear or quasi-collinear interaction between the light pulse and a sound beam, the result from the filtering being used on the non-diffracted direct light beam from the acousto-optic interaction.

Method and device for controlling the amplitude of the wavelength spectrum of ultra-short light pulses emitted by multipass laser amplifiers

Terminal pins (18) in a terminal pin strip (16) are integrally interconnected by webs (22) located intermediate free insertion ends (18i) and free connector ends (18c) of the pins so that when the webs are severed to separate the terminal pins, the severing operation does not disrupt the integrity of smooth finished surfaces on the connector ends of the pins. Each terminal pin (18) also is formed with an intermediate push shoulder (18ps) for applying pressure on the pin to insert the pin into an aperture (20a) in a support structure, such as a printed wiring board (20), without damaging the connector end (18c) of the pin. Assembly of the terminal pins (18) into the printed wiring board (20), utilizing terminal pin strips (16) on respective supply reels (24), is accomplished with apparatus comprising a pair of pin transporter mechanisms (26), a pair of web-severing punch-and-die mechanisms (28), and a pin insertion mechanism 30.

Intermediate-web held terminal pins

An acousto-optic band reject light filter is disclosed. The light filter includes an optically anisotropic medium, such as a birefringent crystal, in which an acoustic wave is excited at a certain selected radiofrequency corresponding to a selected optical frequency to be rejected. The crystal is disposed to receive an incident light beam containing the selected optical frequency to be rejected. The light beam is collinearly diffracted on the acoustic wave within the optically anisotropic medium to diffract light of a first polarization and of the selected optical frequency related to the acoustic frequency into light of a second polarization. The diffracted light beam is then passed through a polarization analyzer to reject from the diffracted light beam light of the second polarization while retaining in the diffracted light beam light of the first polarization. The selectable frequency in the light beam which is to be rejected can be tuned over a wide band by tuning the frequency of the acoustic wave within the crystal.

Heara John R

Papers

Acousto-optic band reject light filter and apparatus using same