281 results about "Beam divergence" patented technology

An optical delivery waveguide for a material laser processing system includes a small lens at an output end of the delivery waveguide, transforming laser beam divergence inside the waveguide into a spot size after the lens. By varying the input convergence angle and / or launch angle of the laser beam launched into the waveguide, the output spot size can be continuously varied, thus enabling a continuous and real-time laser spot size adjustment on the workpiece, without having to replace the delivery waveguide or a process head. A divergence of the laser beam can also be adjusted dynamically and in concert with the spot size.

A high data rate communication system operating at frequencies greater than 70 MHz and at data rates of about 1.25 Gbps or greater. Preferred embodiments include modulators with a resonant LC circuit including a diode which is back-biased for “off” (i.e., no transmit) and forward biased for “on” (or transmit). The modulator is a part of high performance transceivers for wireless, millimeter wave communications links. A preferred embodiment provides a communication link of more than eight miles which operates within the 71 to 76 GHz portion of the millimeter spectrum and provides data transmission rates of 1.25 Gbps with bit error rates of less than 10−10 . A first transceiver transmits at a first bandwidth and receives at a second bandwidth both within the above spectral range. A second transceiver transmits at the second bandwidth and receives at the first bandwidth. The transceivers are equipped with antennas providing beam divergence small enough to ensure efficient spatial and directional partitioning of the data channels so that an almost unlimited number of transceivers will be able to simultaneously use the same spectrum. In a preferred embodiment the first and second spectral ranges are 71.8+ / −0.63 GHz and 73.8+ / −0.63 GHz and the half power beam width is about 0.2 degrees or less. Preferably, a backup transceiver set is provided which would take over the link in the event of very bad weather conditions. In other embodiments especially useful for mobile applications at least one of the transceivers include a GPS locator.

A projection video display includes at least one laser for delivering a light beam. The display includes a beam homogenizer and a condenser lens. A scanning arrangement is provided for scanning the light in beam in a particular pattern over the condenser lens in a manner that effectively increases the beam divergence. The scanned beam is homogenized by a beam homogenizer and a spatial light modulator is arranged to receive the homogenized scanned light beam and spatially modulate the beam in accordance with a component of an image to be displayed. Projection optics are projecting the homogenized scanned light beam onto a screen. The scanning provides that the homogenized scanned light beam at the screen has a coherence radius less than the original coherence radius of the beam. The reduced coherence radius contributes to minimizing speckle contrast in the image displayed on the screen. The screen includes one or more features providing a further contribution to minimizing speckle contrast in the displayed image. In one example, the screen includes a transparent cell containing a liquid having light scattering particles in suspension.

A technique for acquiring and tracking terminals in a free-space laser communication system involves exchanging beacon laser beams between the terminals to acquire and then track the terminals such that data laser beams exchanged by the terminals for communication are steered based on feedback from detection of the beacon laser beams. The beacon laser beams used for acquisition have a greater beam divergence than those used for tracking. Gimbals provide coarse steering of the data laser beams, and steering mirrors provide fine steering. GPS position data exchanged via an RF link can be used for initial pointing of the beacon laser beams for acquisition. The beacon laser beams can be chopped such that all terminals can use the same beacon wavelength and are distinguished by using different chopping frequencies. By detecting a chopped signal, the position sensor detector can be AC coupled to reduce sensitivity to solar radiation and glint.

Apparatus for shaping an optical beam bundle carrying a plurality of substantially parallel optical beams disposed in a common plane of travel. First reflective facets and second reflective facets are provided, the first reflective facets being oriented so as to deflect the optical beams of the bundle into a plurality of intermediate, substantially non-parallel optical beams. Each of the second reflective facets is spatially disposed so as to receive a respective one of the intermediate optical beams at a different respective distance from the plane of travel of the optical beam bundle. Also, the second reflective facets are oriented so as to deflect the intermediate optical beams into a bundle of substantially parallel output optical beams. In this way, the output beam can be more adapted for a particular application. In certain cases, this also achieves increased brightness of a laser beam through reduced output beam divergence and / or total cross-sectional area.

A beam alignment chamber comprising: a base, first and second side walls connected to the base, and a front wall located at the front edge of the base having an output opening. The beam alignment chamber further including a plurality of light sources disposed to direct light beams through the first or second side walls, a plurality of reflectors mounted on the base, each having independent yaw and pitch adjustments, each being disposed to direct the light beams from a corresponding light sources along the length of the beam alignment chamber through the output opening forming an aligned array of parallel light beams, and one or more optical elements positioned in the optical path of the aligned array of light beams disposed to correct the beam divergence with respect to at least one axis.