The Boeing Company

Rockwell International Corporation

Blair F Campbell

Dennis M Guthals

Daniel J Sox

Margarita A Carbon

Steven Edward Muenter

Richard B Holmes

Sam S Ma

A system for path compensation of multiple incoherent optical beams incorporates an optical element combining a plurality of incoherent beams to an aperture by angle using carrier frequency tilt fringes. An illumination laser is employed for reflection of an illumination beam from a target. An interferometer receives a sample of the reflected illumination beam reflected from the target and provides interference fringes. A spatial light modulator receives the interference fringes and generates a real time hologram. Relay optics are employed for transmitting the combined plurality of incoherent beams to the SLM and receiving a diffraction corrected full aperture compensated combined beam for emission to the far field.

Incoherent beam combining of parallel beams with optical path compensation using real time holography

A system for path compensation of multiple incoherent spectral optical beams incorporates an optical element combining a plurality of incoherent spectral beams to an aperture by angle using carrier frequency tilt fringes. An illumination laser is employed for reflection of an illumination beam from a target. An interferometer receives a sample of the reflected illumination beam reflected from the target and provides interference fringes. A spatial light modulator receives the interference fringes and generates a real time hologram. Relay optics are employed for transmitting the combined plurality of incoherent beams to the SLM and receiving a diffraction corrected full aperture compensated combined beam for emission to the far field.

Incoherent spectral beam combining with optical path compensation using real time holography

Blazing of real time holographic fringes employs an interferometer with a focal plane array (FPA) to receive interference fringes. An FPA frame is read into a fringe processor. For each row, minima are identified and a pixel value is saved and its position in the row recorded. The minima determination is repeated for each column in the row until all pixels in the row have been recorded. A blazed fringe for the single row is then created. The blazed fringe row is then transferred to a spatial light modulator (SLM). The minima determination and fringe blazing processes are repeated until all rows in the FPA array are read and transferred to the SLM. The next FPA frame is then read into the fringe processor.

Method for real time holographic fringe blazing by determining adjacent fringe minima and blazing intermediate the minima

A holographically, self-referenced interferometer may include a detector to detect interference fringes in a reference leg optical signal. The interferometer may also include a holographic correction device to holographically compensate the reference leg optical signal in response to the detected interference fringes.

Holographically compensated, self-referenced interferometer

The laser range finding apparatus includes an optical relaxation oscillator assembly, outcoupling optics, a photodetector and a controller. The optical relaxation oscillator assembly produces relaxation oscillations. The relaxation oscillations are a series of optical pulses having a controllable repetition rate. The outcoupling optics receives the series of optical pulses and redirects a minor portion of the energy of the series of optical pulses. A major portion of the energy of the series of optical pulses is adjusted in accordance with first desired beam propagation parameters. A photodetector receives the minor portion and converts the minor portion to an electrical signal representative of the series of optical pulses. A controller receives the electrical signal and determines the repetition period between the optical pulses. The controller provides a controller output to the optical relaxation oscillator assembly for adjusting the controllable repetition rate of the series of optical pulses produced by the optical relaxation oscillator assembly. During operation, the major portion of the energy of the series of optical pulses is directed to a reflecting target, reflected therefrom, collected by the outcoupling optics, and directed back to the optical relaxation oscillator assembly to stimulate subsequent relaxation oscillations, thus locking the period of the relaxations oscillations to the time of flight of the roundtrip path between the laser finding apparatus and the reflecting target.

Laser range finding apparatus

FIG of the drawings has been amended to include arrows and . The word &ldquo;laser&rdquo;, the arrow symbol underneath the word &ldquo;laser&rdquo; and the partial sinusoidal symbol adjacent the word &ldquo;laser&rdquo;have all been deleted. In addition, the word &ldquo;photodetector&rdquo; deleted and a dashed line circumscribing the photodetector componants has been added along with reference numeral . Reference numeral has been added to denote the photodiode. Finally, the photodiode symbol associated with oscillator apparatus has been changed to simply indicate a &ldquo;Gain Cavity&rdquo; box. The attached &ldquo;Replacement Sheet(s)&rdquo;of drawings include changes to FIG. . The attached &ldquo;Replacement Sheet(s),&rdquo;which include(s) FIG(S.) and , replace the original sheet(s) including FIG(S.) and .

A filtering apparatus 30 passes an incident beam of light through a first lens having a first focal length, causing the incident beam of light 32 to be focussed, and then passes the incident beam of light through a pinhole 36 having an opening of a predetermined size. In accordance with one aspect of the invention, the pinhole 36 is spaced from the first lens 34 by a distance which is greater than, or less than, but not equal to the lens' focal length wherein only a portion of the incident beam of light passes through the opening of the pinhole 36. In the illustrated embodiment, the pinhole 36 has a size which is significantly larger than the nominal diffraction limited spot size of the first lens 34. The incident beam of light which passes through the pinhole is then directed toward a second lens 38 having a second focal length. In a preferred embodiment, the second lens 38 is spaced from the pinhole 36 by a distance substantially equal to the second lens' focal length. Because of the increased size of the pinhole and the non-focal length spacing between the pinhole and the first lens 34, the pinhole 36 is able to block substantially all of the phase varying portion of the wavefront of the incident beam yet the sensitivity of the filter to intensity variations and component misalignments is substantially reduced.

Growing community of inventors

Chatsworth, CA, United States of America

Blair F Campbell