Abstract:
A method of producing color and texture effects on a surface (210, 400) without the use of pigments or actual texturing. Diffraction patterns generated by interference between two light beams (220, 230) are recorded in a suitable high-resolution photographic material (210, 400) and are used instead of paints or inks to provide desired color and texture effects in the various regions (440, 530) of an artistic or decorative composition. The resulting composition (210, 400) may contain spectrally pure or mixed colors and a wide range of static or dynamic textural illusions visible under a variety of lighting conditions.
Abstract:
Apparatus and method for producing a plurality of holographic diffraction gratings wherein two or more interfering beams (24) are generated by means of an apertured mask (20). The mask is formed with one or more aperture (22) and is located in the path of the light source (12) and acts to baffle or block the light such that the light passes through only in the region of the apertures thereby creating the number and angle of beams required.
Abstract:
An optical modulator (19) utilizes a variable beam splitter arrangement having two separate plano-periodic cylindrical lens arrays (20 and 22) arranged as a sandwiched air-spaced assembly with the plano surfaces facing outwardly from the assembly. The assembly further includes a means (26) for controllably translating or moving one of the lenses relative to the other. The periodic array is formed as alternating concave and convex cylindrical structures. In a nominal setting, the optical axes of the concave structures of one of the lens arrays are aligned with the optical axes of the convex structures of the other so that the assembly acts as an afocal window having little impact when placed in an optical system. To adjust the beam splitting properties, one lens array is slightly translated with respect to the other to cause controlled misalignment of the two lens array surfaces. The present invention is particularly suited for tuning the point spread function of an electronic imaging system.
Abstract:
A diffractive, multifocal ophthalmic lens including an apodization zone with echelettes having a smoothly reduced step height to shift the energy balance from the near image to the distant image and thus reduce the glare perceived when viewing a discrete, distant light source.
Abstract:
A simulated opal article, including a layer (1) of a reproduction of a surface of an opal applied to the surface of a two-dimensional hologram or diffraction grating (2) formed from two randomed patterned orthogonally embossed holograms or diffraction gratings. The two-dimensional hologram or diffraction grating (2) is formed by embossing a first pattern onto a suitable embossable surface with a second pattern double embossed or superimposed over the first pattern in such a manner that both patterns are visible at similar intensity and become interactive, thereby creating an interactive spectrogram with a three-dimensional effect resembling an opal and being sufficiently flexible so that it may be adhered to a flat, convex, concave, uneven or undulating surface.
Abstract:
A method and apparatus for fabricating submicron periodic gratings (90) and other fine patterns in photoresist at a resolution which is beyond the capability of conventional UV lithography. A transparent mask tool (10) is utilized having first and second transparent regions which are separated by an opaque region (40). The transparent regions each have a top surface and a bottom surface. An optical grating having a first period is placed on the top surface of the first and second transparent regions. An optical grating having a second, finer period is placed on the bottom surface of the first and second transparent regions. The central opaque region is sized according to the dimensional requirements of the exposure ultimately required on the photoresist. In the method of the present invention, a linearly polarized monochromatic light (80) is used to illuminate the mask tool, thereby creating first and second diffracted beams which reach the area under the center opaque region. The beams interfere only in the area (76) under the center opaque region, thus yielding a finer grating structure, having a period, or size, of 1/4 the original period of the mask tool.
Abstract:
A light transmitting device comprising or incorporating a broadband Bragg grating that is formed in the direction of light propagation with grating regions of alternatingly high and low refractive index. The grating regions are formed with periodicity P and are structured as to amplitude, periodicity and/or phase in a manner which varies periodically with a modulation period L > P. Also, either one or the other or both of the grating period P and the modulation period L is or are chirped over substantially the full extent of the grating. The grating exhibits a spectral response in which broad reflection peaks appear at each side of a reflection peak centred on the Bragg wavelength and fall under an envelope determined by the Fourier transform of the periodic modulation function.
Abstract:
Lenses having diffractive features and optical systems employing such lenses are presented. In a first embodiment, an optical lens assembly comprises a housing (12), a lens (14) mounted therein, an open end, and a sized aperture (22) in the other end. The lens is bi-convex aspheric with diffractive features on both surfaces (28), (30), and performs the function otherwise requiring a plurality of lenses. The aperture accomplishes vignetting and defines the bundle size of light received by the lens. In a second embodiment, an optical assembly comprises a housing having two lenses mounted therein, and an aperture stop. Light entering the first lens passes through the aperture stop, enters the second lens and is focused by the second lens. The first lens comprises a convex spheric surface and an opposing concave aspheric surface. The second lens comprises a convex aspheric surface having diffractive features and an opposing convex aspheric surface. The invention is well suited for use with CCD cameras and other applications.
Abstract:
Optical energy tranfer devices and energy guiding devices (700, 770) use an electric field to control energy propagation using a class of poled structures in solid material in a channel dropping filter and splitter applications. The poled structures, which may form gratings (706, 753) in thin film or bulk configurations, may be combined with waveguide structures (712, 713, 752, 772). Electric fields applied to the poled structures control routing of optical energy. In a particular embodiment, an electrode (710) confronts a solid material and bridges at least two elements of a grating (706) disposed transverse of two wavegide segments (712, 713) and overlaps evanescent fields of optical energy in one of the waveguide segments. A switchable grating (706) may be used by itself, or in combination with other gratings to form integrated structures.
Abstract:
A grating structure has a series of raised and sunk surfaces of optical quality. The object of the invention is to develop an appropriate diffraction optical grating by applying the principle of wave front distribution, as well as the use of this grating. For that purpose, the differences in height between adjacent raised and sunk surfaces have at least four different values.