Abstract: An integrated micro-optical system includes at least two wafers with at least two optical elements provided on respective surfaces of the at least two wafers. An active element having a characteristic which changes in response to an applied field may be integrated on a bottom surface of the wafers. The resulting optical system may present a high numerical aperture. Preferably, one of the optical elements is a refractive element formed in a material having a high index of refraction.

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: Mass production of integrated optical subsystems may be realized by providing a bonding material surround each die in an array of first dies on a wafer. A plurality of second dies are then aligned with the dies on the wafer. The bonding material is then treated to bond the aligned dies. The bonded dies are then diced to form a bonded pair of dies containing at least one optical element, thus forming an integrated optical subsystem. The bonding material may be provided over at least part of the optical path of each first die, over an entire surface of the wafer or around the perimeter of each first die. The second dies may be provided on another wafer. Either die may contain active elements, e.g., a laser or a detector. The optical elements may be formed in the die or may be of a different material than that of the die.

Abstract: An optical apparatus for circularizing a laser beam includes a bench having indentations thereon and optical elements provided in these indentations. A first optical element has a high numerical aperture. A second optical element collimates the beam output by the first optical element and is spaced from the first optical element. This spacing is determined in accordance with a location of the beam output by the first optical element at which the beam will be most circular. The indentation in which the second optical element is placed may be both vertically and horizontally displaced from the indentation in which the first optical element is placed.

Abstract: A substrate having an optical element on an input surface thereof receives a light beam not having a desired beam shape and shapes the light beam into a predetermined intensity distribution. The substrate may further include a second optical element for providing a predetermined phase pattern to the light beam provided by the first optical element. The first optical element may, for example, circularize an elliptical light beam using a soft aperture for differential power attenuation or by altering the divergence of the light beam along the different axes of the light beam. When the divergence angles are altered and the collimating optical element is provided on the output surface, the thickness of the transparent substrate is determined in accordance with a resultant difference in the divergence and/or with the initial difference in beam size along each axis and with a required circularity.

Abstract: A broadband diffractive diffuser contains at least three levels, with approximately a phase shift of .pi. between at least two of the at least three levels. Such a diffuser provides light with more than two phasor vectors at the zero order. The presence of the more than two phasor vectors reduces the zero order diffraction efficiency at non-design wavelength, increasing the usefulness of the diffuser at wavelengths other than the design wavelength. Preferably, the diffractive diffuser includes a plurality of regions, approximately 50% of an area of the plurality of regions presenting a phase shift of .pi. at a design wavelength, approximately 25% of the area of the plurality of regions presenting a phase shift of 2.pi. at the design wavelength, and approximately 25% of the area of the plurality of regions presenting a phase shift of 0 at the design wavelength.

Abstract: An integrated optical apparatus includes an optically transparent substrate with a light source and a detector mounted adjacent thereto. The substrate includes an optical element in a transmit path from the light source to a remote target. The optical element splits the light into more than one beam. A detector receives beams reflected by the target. All optical elements needed to create the more then one beam, direct the more than one beam onto the target and direct the more than one beam from the target to the detector are on the substrate and/or any structure bonded to the substrate. Preferably, the optical element provides sufficient separation between the more than one beam such that each beam is delivered to a unique respective light detecting element of the detector. The return path from the remote target to the detector may include an optical element for each beam or no optical elements. An additional substrate may be included and bonded to the substrate.

Abstract: Integrated multiple optical elements may be formed by bonding substrates containing such optical elements together or by providing optical elements on either side of the wafer substrate. The wafer is subsequently diced to obtain the individual units themselves. The optical elements may be formed lithographically, directly, or using a lithographically generated master to emboss the elements. Alignment features facilitate the efficient production of such integrated multiple optical elements, as well as post creation processing thereof on the wafer level.

Abstract: A diffusing function and a lens function are provided on a single surface. Such a structure may be formed from a computer generated hologram including free form regions having a phase shift associated therewith, i.e., the computer generated hologram being shifted within the free form regions by the phase shift relative to the computer generated hologram outside the free form regions. When the computer generated hologram includes zero and .pi. regions, the zero and .pi. regions may be transposed within the free form regions.

Abstract: Gray scale masks used to create optical elements are formed. Desired gray scale patterns may be created by varying the thickness of a light absorbing layer. Such variations in thickness may be created using multiple binary masks. Desired gray scale patterns may also be created on a computer using available software and then imaged onto film or a glass film plate. Direct contact or proximity printing is then used to transfer the true gray scale pattern onto photoresist. The photoresist is then etched, thereby forming the desired pattern therein. All portions of the desired pattern are simultaneously formed in the photoresist. The etched photoresist is then used to photolithographically fabricate either the optical element itself or a master element to be used in injection molding or other replication techniques. The gray scale mask itself may be used repeatedly to generate photoresists. The imaging is particularly useful for forming optical elements having a plurality of arrays of refractive elements.

Abstract: An integrated micro-optical system includes at least two wafers with at least two optical elements provided on respective surfaces of the at least two wafers. An active element having a characteristic which changes in response to an applied field may be integrated on a bottom surface of the wafers. The resulting optical system may present a high numerical aperture. Preferably, one of the optical elements is a refractive element formed in a material having a high index of refraction.

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: A soft aperture allows gradual attenuation of a light beam dependent upon its location away from the center of a diffractive optical element. Such an optical element may be provided by decreasing a number of phase levels, increasing a number of phase levels, increasing a density of metal patches or diffractive gratings, or decreasing a blaze height and/or duty cycle, all radially from the center. Alternatively, the soft aperture may be defined by a photolithographic process. Such a soft aperture is particularly useful in aiding circularizing of an elliptical light beam. The soft aperture may be used alone or integrated with other optical elements.

Abstract: An optical element is formed as a body having two layers, at least on of which is transmissive to a selected wavelength of a light of illumination. One layer is formed with a first surface relief optical formation as a boundary thereof, and the other layer is formed on the boundary so as to have an adjacent boundary that is a second surface relief optical formation that is the conjugate of the first surface relief optical formation. The other layer also has further optical features on a surface opposite the adjacent boundary. The formation and features are preferably diffractive. The further optical features opposite the adjacent boundary is preferably a compensated conjugate of the formation at the adjacent boundary.

Abstract: A method of patterning a plurality of optical rods includes bonding a plurality of optical rods into an array wherein each of the optical rods is aligned so that an exposed end face of each of the optical rods is oriented in a common direction. The exposed end faces of the optical rods are patterned so that each of the exposed end faces has a three-dimensional pattern formed thereon. These patterned optical rods can then be separated and used in the fabrication of optical systems.

Abstract: A laser diode power controller, and method, are disclosed. The controller can be implemented entirely in CMOS technology due to the simplicity of its quasi-decision-based control routines. The control routines involve the use of a window comparator which determines whether the measured power level of a laser diode falls within a desired range of values. The simplified control routines are also manifested by the use of digital registers to set the desired current values that are to be output to the laser diode and monitor diode. The modulation current supplied to the laser diode exhibits much lower noise levels because the modulation digital to analog converter (DAC) By supplying a continuous current that is selectively switched between the laser diode and a dummy load, much less noise is induced in the power supply than if it had to respond to large changes in modulation current, i.e., OFF (zero) and ON (desired Imod).

Abstract: An integrated optical apparatus includes an optically transparent substrate with a light source and a detector mounted adjacent thereto. The substrate includes an optical element in a transmit path from the light source to a remote target. The optical element splits the light into more than one beam. A detector receives beams reflected by the target. All optical elements needed to create the more then one beam, direct the more than one beam onto the target and direct the more than one beam from the target to the detector are on the substrate and/or any structure bonded to the substrate. Preferably, the optical element provides sufficient separation between the more than one beam such that each beam is delivered to a unique respective light detecting element of the detector. The return path from the remote target to the detector may include an optical element for each beam or no optical elements. An additional substrate may be included and bonded to the substrate.

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: 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.