USA as Represented by Secretary of the Navy

Frank E Hanson

Charles S Bendall

Peter M Poirier

David Dick

A method involves obtaining a first beam image on a focal plane of a first camera and a second beam image on a focal plane of a second camera from light scattered by ambient atmospheric aerosols in the path of a laser beam. First and second projected beam images are formed, representing the respective first and second beam images in the projected scenes of the respective first and second cameras. First and second ambiguity planes are then formed from the respective first and second projected beam images. An intersection of the first and second ambiguity planes is then determined, identifying the position of the laser beam. A source of the laser beam is then determined, along with a camera-source plane. A beam elevation angle with respect to this plane is then determined, as well as beam azimuth angles with respect to lines between the respective camera and the source.

Method for atmospheric laser beam detection using remote sensing of off-axis scattering

A Q-switched neodymium laser may be operated in the 0.9 &mgr;m &lsqb;( &lgr;,)&rsqb; band at relatively high gain levels. The laser uses a birefringent filter which provides selective discrimination for wavelengths near 1 &mgr;m &lsqb;(&lgr;,)&rsqb; and prevents parasitic lasing in that wavelength region. The filter includes a specific wavelength dependent crystal quartz wave plate in combination with a linear polarizer. The linear polarizer is placed between two mirrors which define a laser cavity. The wave plate provides exactly 2 full waves of retardation at the desired wavelength &lgr;,in the 0.9 &mgr;m band, and exactly 1.75 waves of retardation at wavelength &lgr;,near the center of the 1 &mgr;m band for one pass. A Q-switching device such as a Pockels cell is positioned in the laser cavity to selectively control a pulsed emission at &lgr;,.

High energy Q-switched 0.9 &mgr;m laser

A solid state laser comprises a composite solid state laser gain element, The gain element comprises a undoped section and a doped section having a concentration of dopant ions for absorbing pumping radiation. The doped section is diffusion bonded to the undoped section to form an active region in the gain element, A cooling jacket conducts flowing coolant around the circumference of a portion of the gain element surrounding the active region.

Cooling device for solid state laser

An optical blue parametric generation relies upon a nonlinear optical cryl of lithium borate (LiB.sub.3 O.sub.5) properly oriented to generate blue light when appropriately located in a resonant optical cavity and pumped with high intensity light at 355 nm. Beam walk-off and beam pump divergence are greatly reduced due to a specific orientation of non-critical phase-matching so that the 355 nm pump source provides for a sufficient phase-match for output generation near the H Beta Fraunhofer wavelength at 486 nm and also provides for a temperature tuning of the lithium borate crystal to permit exact coincidence to a particular output wavelength so that optical parametric generation from 470 to 487 nm may be assured by the appropriately tuned lithium borate crystal.

Blue generation at the H-Beta Fraunhofer wavelength using noncritically

A solid state laser rod of an anisotropic material is more efficiently side pumped by using cylindrical lenses and a half-wave plate with linear laser diode arrays disposed along the length of the solid state laser rod such that the polarization of the diode array light is rotated to achieve a maximum absorption coefficient in the laser rod material. In addition, Fresnel reflection losses at the lens and laser rod surfaces are reduced by a 90.degree. polarization rotation.

Growing community of inventors

San Diego, CA, United States of America

Frank E Hanson