Abstract: A beam homogenizer that minimizes undesired intensity variations at the output plane caused by sharp breaks between facets in previous embodiments. The homogenizer includes a hologram made up of irregularly patterned diffractive fringes. An input beam illuminates at least part of the hologram. The hologram transmits a portion of the input beam onto an output plane. In doing so, the energy of the input beam is spatially redistributed at the output plane into a homogenized output beam having a preselected spatial energy distribution at the output plane. Thus, the illuminated portion of the output plane has a shape predetermined by the designer of the homogenizer.

Abstract: A method of fabricating a diffractive optical element includes the steps of: etching a negative of a desired multi-level diffraction pattern onto a molding surface of a quartz master element using photolithography, assembling the master element as a portion of a mold,and injecting a plastic molding composition into the mold and against the molding surface of the master element to injection mold a diffractive optical element whereby the optical element has the desired diffraction pattern on its surface. The diffraction pattern is preferably formed on the quartz master using VLSI photolithography.

Abstract: An integrated optical head, such as, for a disk drive, preferably includes an optically transparent substrate. The substrate has a diffractive optical element formed on one face and a plurality of electrical contact pads exposed on the other face. A light source is positioned to emit light through the substrate, through the diffractive optical element, and toward data storage media. The light source includes a plurality of electrical contact pads corresponding to the plurality of electrical contact pads exposed on the face of the substrate. An optical detector is positioned to detect light reflected from the data storage media, through the diffractive optical element, and through the substrate. The optical detector includes a plurality of exposed electrical contact pads corresponding to the plurality of electrical contact pads exposed on the face of the substrate. The substrate and the light source and optical detector are passively aligned using solder bumps between pairs of contact pads.

Abstract: A method of fabricating a diffractive optical element includes the steps of: etching a negative of a desired multi-level diffraction pattern onto a molding surface of a quartz master element using photolithography, assembling the master element as a portion of a mold, and injecting a plastic molding composition into the mold and against the molding surface of the master element to injection mold a diffractive optical element, whereby the optical element has the desired diffraction pattern on its surface. The diffraction pattern is preferably formed on the quartz master using VLSI photolithography.

Abstract: An improved optical system is disclosed for projecting light in the form of an image to a remote target. The laser light source and a holographic optical element are mounted together in optical alignment. The optical element is created using iterative discrete computer encoding for optimum efficiency. In alternate embodiments, the diffractive optical element has a collimating lens encoded into the grating levels and it also performs soft aperture circularizing using either amplitude or phase control over the coherent light. An embossed diffractive optical element laminated to an injection-molded refractive element is also disclosed.

Abstract: A beam homogenizer for converting an incident beam of non-uniform spatial power or energy distribution into an output beam of uniform spatial power or energy distribution. The homogenizer is a holographic optical element constructed from an array of facets or subholograms and positioned at a first plane in the path of an incident signal. The transmittance from each subhologram is uniformly spread across a target at a second plane that is spaced away from the first plane Another optical element, such as a holographic collimation element, may be placed at the second plane to collimate the transmittances thereupon.

Abstract: A transport for a laser writing and reading system in which a carriage is propelled by a falling mass, either its own or an auxiliary mass. The falling mass works against a hydraulic cylinder and piston in which hydraulic fluid is displaced from the cylinder. A valve limits the flow of hydraulic fluid out of the cylinder so that the fall of the mass, and hence the carriage is braked to a uniform velocity. The system also includes a laser having a beam for scanning in a line transverse to the direction of motion of the carriage. A photosensitive medium is disposed to receive the scanning radiation. Either the laser or the photosensitive medium may be mounted on the carriage, with the other mounted in the fixed position in optical communication therewith. By controlling the rate of fluid flow through the valve, the mass will fall with uniform velocity, thereby propelling the carriage at a uniform, vibration-free rate.