93 results about "Fresnel diffraction" patented technology

A variable focal length lens comprising micromirrors with pure translation is invented. The lens consists of many micromirrors and actuating components. The array of micromirrors with pure translation makes all lights scattered from one point of an object have the same periodic phase and converge at one point of image plane by using Fresnel diffraction theory. The actuating components control the positions of micromirrors electrostatically and / or electromagnetically. The optical efficiency of the micromirror array lens is increased by locating a mechanical structure upholding micromirrors and the actuating components under micromirrors. The known semiconductor microelectronics technologies can remove the loss in effective reflective area due to electrode pads and wires. The lens can correct aberration by controlling each micromirror independently. Independent control of each micromirror is possible by known semiconductor microelectronics technologies. The micromirror array can also form arbitrary shape and / or size of a lens.

A method and system for encrypting multi-dimensional information utilizing digital holography is presented. A phase-shifting interferometer records the phase and amplitude information generated by a three-dimensional object at a plane located in the Fresnel diffraction region with an intensity-recording device. Encryption is performed by utilizing the Fresnel diffraction pattern of a random phase mask. Images of different perspectives of the three-dimensional object focused at different planes can be generated digital or optically with the proper key after decryption.After decryption, images of the object, focused at different planes, can be generated digitally or optically. The method allows for the reconstruction of the object with different perspectives from a single encrypted image. The method does not require sending the key exclusively through a digital communication channel. Instead, a copy of the random phase key itself can be sent to the authorized user.A method of forming an image of an object is disclosed. The method comprises forming an original hologram of the object; compressing the original hologram of the object to form a compressed hologram; decompressing the compressed hologram of the object to form a decompressed hologram; and reconstructing the object from the decompressed hologram to form a multi-dimensional image of the object.

The present invention provides a technique enabling to control fringe spacing s and an interference width W independently of each other, which are important parameters for an interferometer using an electron biprism.In the present invention, two electron biprisms 9u, 9b are used in two stages along the optical axis, and fringe spacing s and an interference width W are controlled independently of each other by controlling a voltage applied to an electrode of each of the electron biprisms. Also Fresnel diffraction can be suppressed.

Mask Shaping using temporal and spatial Coherence for Ultra High Resolution Lithographic imaging and printing refers to methods and apparatus that can be adopted to print near-ideal images of basic shapes when the shapes are asymmetrical. Ultra High Resolution Lithography refers to proximity printing of clear mask fetures when they are demagnified by bias. In this lithography, optical components, including lenses and mirrors, are not used between the mask and wafer. When a clear mask feature is asymmetric and the mask-wafer gap is set so that the Critical Condition is maintained for the shortest print dimension, then undesirable features typically appear in other longer dimensions consistent with Fresnel diffraction. The undesirable featurs impede illumination uniformity for controlled printing in exposed areas. Such features, including Bright Spots and Ripple, are counteracted by the Mask Shaping that is designed to optimize printing with temporal and spatial coherence near the Critical Condition. Even with broad band illumination, ultra high resolution is not lost. On the contrary, with Mask Shaping near the Critical Condition, the undesirable features occurring parallel to the longer dimensions, are normally reduced or eliminated. Near-ideal shapes can be printed. With Mask Shaping for temporal and spatial coherence, production parameters, including resolution, exposure time, and illumination band width can be enhanced, traded, and optimized.