Synrad, Inc.

Lidatek L.l.c.

Yong Fang Zhang

Peter Laakmann

Keith L Hayes

An optical waveguide and method for guiding a laser beam through a channel member having a fluid medium disposed therein. A refractive index gradient is created in the fluid medium which causes the fluid medium to guide the laser beam through the channel member. The refractive index gradient results when a temperature index gradient is created in the fluid medium by heating the channel member wall. The channel member can be externally heated using a separate heating source or the channel member can be heated from the inside by the laser beam itself. A fluid pump is used to create a fluid flow in the fluid medium in order to maintain the temperature and refractive index gradients in the fluid medium.

Graded refractive index optical waveguide using a fluid medium

A laser transponder and method for disabling a laser-based speed monitor of the type that transmits a monitor laser beam at a moving motor vehicle. The monitor laser beam transmitted by the speed monitor is detected when it arrives at the motor vehicle. In response to detecting the monitor laser beam, a warning is output to the motor vehicle driver and a jamming laser beam is transmitted toward the speed monitor. The jamming laser beam includes a plurality of pulses separated from each other by a time period that is less than or equal to an amount of time needed for the monitor laser beam to travel from the speed monitor to the motor vehicle and back to the speed monitor. The jamming laser beam disables the speed monitor for a time period sufficient to allow the motor vehicle driver to reduce the speed of the motor vehicle.

Laser transponder and method for disabling laser speed monitors

A laser scanner having first and second scanning mirrors and a correction circuit that removes distortions caused by interaction between the scanning mirrors. Preferably, the first scanner mirror is an off-axis mirror that is positioned to produce a single, substantially invariant pupil on the second scanning mirror. Preferably the scanner uses a reflective beam expander to magnify an input laser beam received from a laser source. Preferably, the reflective beam expander is implemented using two spherical mirrors positioned to form the input laser beam into a Z-folded beam path. The folded beam path increases the distance between the laser source and the focusing lens, which results in a clear focused spot and does so using spherical mirrors which are much less expensive than the infrared lenses used in the prior art. The reflective beam expander is also wavelength insensitive. In one embodiment, the correction circuit employs analog elements to implement a quadratic approximation of the geometric distortions caused by interaction of the scanning axes. In another embodiment, the correction circuit employs programmable logic devices to create corrected mirror control signals based on correction values stored in digital memory units.

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Kirkland, WA, United States of America

Yong Fang Zhang