摘要:
A high frequency spectral analysis system and method operates by modulating an optical beam with a high frequency signal to be analyzed, and sampling the beam simultaneously at periodically spaced locations along its length. The sampled portions are then focused to a spectral mapping. In the preferred embodiment a beam is directed in a zigzag pattern through a plate, one surface of which is totally reflective and the opposite surface of which is partially reflective. Periodic parallel samples are obtained from the minor portions of the beam which are transmitted out of the plate through the partially reflective surface. The totally reflective surface is preferably formed as a series of cylindrical surfaces which focus the beam to small spots at the partially reflective surface, thereby permitting a higher spatial density of samples without overlapping. The plate thickness is selected so that the beam is sampled at the Nyquist rate for the highest frequency contained in the signal of interest.
摘要:
Optical data processing systems are described for processing four NxN matrices A, B, C, D to calculate the expression CA.sup.-1 B+D. Multi-cell spatial light modulators are employed in conjunction with control circuits to perform matrix inversion, multiplication and addition.
摘要:
Apparatus for performing a division of a dividend intensity array by a divisor intensity array on a pixel-by-pixel basis, to yield a quotient intensity array, wherein optical feedback principles are utilized in conjunction with two spatial radiation modulators, so that analog division is achieved. Specifically, a fraction of the output array of a first spatial radiation modulator is provided as the readout array to a second spatial radiation modulator, whose input is the divisor intensity array. The output array of the second image converter is then added to the dividend array and provided as the input to the first spatial radiation modulator, whereupon the output of the first spatial radiation modulator is the pixel-by-pixel quotient array resulting from division of the dividend array by the divisor array.
摘要:
Associative holography memory apparatus is disclosed which employs a hologram and two phase conjugate mirrors. The mirrors are arranged to form a conjugate resonator whereby the output image from the apparatus tends to converge to that stored image most closely associated with an input image. Alternate embodiments are described which employ a multiple storage and erasure hologram, and which employ only a single phase conjugate mirror.
摘要:
Optical analog data processing systems are described for handling both bipolar and complex data. Multi-cell spatial light modulators are employed in which a plurality of modulation areas are used in conjunction with space and time mutliplexed configurations to process bipolar and complex data elements. Multi-cell light detector arrays are used to convert modulated light into signals representing the processed data. The processing systems are capable of real time processing of synthetic aperture radar data.
摘要:
Associative holography memory apparatus is disclosed which employs a hologram, two phase conjugate mirrors, and a two-wave mixing contra-directional coherent image amplifier. The mirrors and amplifier are arranged to form a conjugate resonator whereby the output image from the apparatus tends to converge to that stored image most closely associated with an input image. Alternate embodiments are described which employ a multiple storage and erasure hologram, and which employ only a single phase conjugate mirror.
摘要:
There is disclosed a system capable of subtracting in real time the intensities of two incoherently illuminated scenes and providing the sign of the subtracted information. The system utilizes two birefringent devices such as liquid crystal light valves, onto which the two images to be subtracted are projected. One valve is analyzed in between crossed polarizers, or equivalent, while the other one is in between parallel polarizers or equivalent. Both polarizer arrangements, for example, may be implemented with a polarizing beam splitter and a quarter wave plate. The common output image plane, onto which both images are superposed, displays an intensity proportional to the difference between the two inputs. This intensity "rides" on a constant background intensity thus displaying the difference signal as well as its polarity. The read-in and read-out beams could be coherent as well as incoherent, the latter being more desirable due to its speckle-free image. No other system is presently known which can perform incoherent subtraction. Experimental results obtained with incoherent illumination are given.
摘要:
A method of optical element manufacturing, the method may include selecting a range of a misfocus parameter ψ; and designing the optical element to include multiple regions, wherein the optical transfer function (OTF) of the optical element allows, for the range of the misfocus parameter .psi., transmission of images with a contrast of at least 10% for all normalized spatial frequencies up to 50% of a theoretical maximum that is attainable with a full aperture in an in-focus condition.
摘要:
A holographic grating element is provided which enables tracing different scan lines. The element is divided into a plurality of sectors. A first grating pattern is provided which diffracts a beam in one direction, and a second grating pattern is next to the first and diffracts the scan beam in the reverse direction. Sectors can be produced with different sector sizes to enable scanning at different rates in the reverse direction, or in successive scans in the same direction. Angle relationships are described to produce diffraction patterns for a desired relationship between disc rotation and the angle of the scan line.
摘要:
An improved optical rotary joint is achieved by transmitting information in the form of an optical signal from a part of the de-spun portion outside the rotational axis to create on the spun portion, or vice versa, 360.degree. about the rotational axis, a continuous communication path having a configuration described by a series of overlapping elliptical areas. The detection area on the spun portion is less than that of the detection path thereby providing continuous optical communication with the transmitted optical signal.