Abstract: An optical apparatus comprises an optical device formed on a device substrate, a first optical waveguide formed on the substrate or on the optical device, and a second, mechanically discrete optical waveguide assembled with the device substrate, optical device, or first optical waveguide. The first optical waveguide is arranged for transferring an optical signal between the optical device and the first optical waveguide. The first and second optical waveguides are arranged, when the second optical waveguide is assembled with the device substrate, optical device, or first optical waveguide, for transferring the optical signal therebetween via optical transverse coupling.

Abstract: An optical apparatus comprises: an optical fiber, an optical device on a substrate, a circuit board, and an electrical connection therebetween. The substrate has a groove for positioning the fiber for optical coupling with the optical device. A proximal segment of the fiber is secured to the substrate in the groove. The substrate is mounted on the circuit board, and a second segment of the fiber is secured to the circuit board. A method comprises: mounting on the circuit board the substrate with the optical device; establishing the electrical connection; securing the proximal fiber segment to the substrate in the groove; and securing the second fiber segment to the circuit board. Multiple substrates can be secured to a single piece of circuit board material, which can be divided into individual circuit boards after establishing electrical connections and securing optical fibers to the corresponding substrates and to the circuit board material.

Abstract: An optical apparatus is made by mounting segments of a GRIN optical medium on a substrate in at least one groove thereon. The GRIN segments are longitudinally spaced apart from one another on the substrate, and are arranged so that a free-space optical beam received through the distal end face of the first GRIN segment is transmitted through the proximal end face of the first GRIN segment, propagates to the proximal end face of the second GRIN segment, is received through the proximal end face of the second GRIN segment, and is transmitted as a free-space optical beam through the distal end face of the second GRIN segment. The GRIN segments can be formed by division of a single GRIN optical medium mounted on the substrate.

Abstract: An optical apparatus comprises segments of a GRIN optical medium mounted on a substrate in at least one groove thereon. The GRIN segments are longitudinally spaced apart from one another on the substrate, and are arranged so that a free-space optical beam received through the distal end face of the first GRIN segment is transmitted through the proximal end face of the first GRIN segment, propagates to the proximal end face of the second GRIN segment, is received through the proximal end face of the second GRIN segment, and is transmitted as a free-space optical beam through the distal end face of the second GRIN segment. The GRIN segments can be derived from a single GRIN optical medium mounted on the substrate.

Abstract: A method comprises computing an interference pattern between a simulated design input optical signal and a simulated design output optical signal, and computationally deriving an arrangement of at least one diffractive element set from the computed interference pattern. The interference pattern is computed in a transmission grating region, with the input and output optical signals each propagating through the transmission grating region as substantially unconfined optical beams. The arrangement of diffractive element set is computationally derived so that when the diffractive element set thus arranged is formed in or on a transmission grating, each diffractive element set would route, between corresponding input and output optical ports, a corresponding diffracted portion of an input optical signal incident on and transmitted by the transmission grating. The method can further comprise forming the set of diffractive elements in or on the transmission grating according to the derived arrangement.

Abstract: An apparatus comprises: a substrate; a photodetector formed on an area of a surface of the substrate; an electrical contact formed on a portion of the photodetector; and a reflector formed over a portion of the photodetector distinct from the portion of the photodetector having the electrical contact formed thereon. The substrate, the photodetector, and the reflector are arranged so that an optical signal to be detected is incident on the photodetector from within the substrate, and at least a portion of the optical signal incident on the photodetector and transmitted thereby on a first pass is reflected by the reflector to propagate through the photodetector for a second pass.

Abstract: An arrow holder comprises: a U-shaped bracket; an arrow catch extending from one side of the bracket toward the other leaving a vertical gap; a spring member for biasing an arrow stack within the bracket against the arrow catch; and opposed arrow guides at the front end of the bracket. The arrow guides extend vertically to constrain horizontally the top arrow of the stack. The bracket, arrow catch, arrow guides, and spring member are arranged for: enabling the top arrow to pivot about the arrow guides and pass through the gap; releasing the top arrow when it pivots sufficiently to clear the arrow catch; and biasing the remainder of the stack against the arrow catch if the top arrow is released. A method comprises pivoting the top arrow thereby releasing it from the arrow holder. The method may further comprise inserting the single stack of arrows into the arrow holder.

Abstract: A multiply-integrated system for inventory, sales, and distribution of products comprises a supplier database, an order database, and a programmed order processor. The supplier database includes inventory/pricing information for multiple independent participating product suppliers, which may include: product manufacturers, distributors, and/or retailers. The order database includes order information received by the multiple participating product suppliers from multiple independent product purchasers. The multiple product purchasers may include any or all of: product manufacturers, distributors, retailers, and/or purchasers.

Abstract: A planar optical waveguide has a set of diffractive elements and confines propagating optical signals in at least one transverse spatial dimension. Each diffractive element set routes, between input and output ports, a corresponding diffracted portion of an input optical signal propagating in the planar optical waveguide that is diffracted by the diffractive element set. The input optical signal is successively incident on the diffractive elements.

Abstract: A method comprises: formulating a design input and output optical signals; computing an interference pattern between the simulated input and output optical signals; computationally deriving a diffractive element arrangement from the computed interference pattern; forming a mask pattern corresponding to the derived diffractive element arrangement; and forming the diffractive element set on a substrate surface by projecting the mask pattern. An optical surface grating comprises a set of diffractive elements on a substrate. The arrangement of the diffractive elements is computationally derived from an interference pattern computed for interference at a substrate surface between a simulated design input and output optical signals. An optical spectrometer comprises: an input optical port for receiving an input optical signal into the spectrometer; an output optical port for transmitting an output optical signal out of the spectrometer; and an optical surface grating as described hereinabove.

Abstract: Data integrity of recorded data products is quantitatively evaluated by enumeration of unreadable, uncorrected, and/or corrected data subsets, and/or by measuring over-sampling of corrected data subsets. Quantitative data integrity evaluation facilitates commerce in pre-owned data products, through pre-owned product re-sellers and/or directly between owners and buyers. Quantitative data integrity evaluation, in conjunction with pre-owned product commerce or performed independently, provides opportunities for gathering product information for data products, including content signature or other unique content-identifying data, for incorporation into product information database(s). Data integrity evaluation, pre-owned data product commerce, and/or data product information gathering may be conducted online. Data integrity evaluation, pre-owned product commerce, and/or data product information gathering may provide opportunities for revenue generation.

Abstract: A spectrally-encoded label comprises a spectrally-selective optical element having a label spectral signature. The label spectral signature is determined according to a spectral-encoding scheme so as to represent predetermined label information within the spectral encoding scheme. The label emits output light in response to input light selected by the label spectral signature of the optical element. A spectrally-encoded label system further comprises an optical detector sensitive to the output light emitted from the label, and a decoder operatively coupled to the detector for extracting the label information according to the spectral encoding scheme, and may also include a light source providing the input light for illuminating the label.

Abstract: A method for generating THz radiation comprises illuminating a semiconductor crystal with an optical pulse train. The semiconductor crystal comprises alternating parallel crystal domains, with each domain having a crystal orientation inverted with respect to adjacent domains. The optical pulse train propagates substantially perpendicularly relative to domain boundaries in the semiconductor crystal. The THz radiation is generated from the optical pulse train by optical down-conversion mediated by the semiconductor crystal. Optical path lengths through the crystal domains at least in part determine a frequency of the generated THz radiation. THz generation efficiency may be enhanced by placing the semiconductor crystal within an external resonant cavity, by placing the semiconductor crystal within a laser cavity, or by placing the semiconductor crystal within an OPO cavity. The semiconductor crystal may comprise zinc-blende, III-V, or II-VI semiconductor.

Abstract: An apparatus comprises an optical transmission element, a diffractive element set formed in or on the transmission element, and an optical component. The diffractive element set is positioned to enable spatial overlap of diffractive elements and an evanescent optical signal propagating in a suitably positioned optical waveguide. The diffractive elements are arranged to establish optical coupling between respective optical signals propagating within the transmission element and the optical waveguide. The optical component is arranged to launch or receive the optical signal propagating within the transmission element. The diffractive element set is arranged so that the optical signal in waveguide is successively incident on the diffractive elements. The optical apparatus can further include the optical waveguide, with the optical waveguide and the transmission element comprising discrete, assembled subunits.

Abstract: An exemplary optical apparatus comprises: an optical element having multiple sets of diffractive elements; and a photodetector. The diffractive elements of each set are collectively arranged so as to comprise corresponding spectral and spatial transformation information for each set. At least two of the sets differ with respect to their corresponding spectral and spatial transformation information. The diffractive elements of each of the sets are collectively arranged so as to transform a portion of an input optical signal into a corresponding output optical signal according to the corresponding spectral and spatial transformation information. At least one photodetector is positioned for receiving at least one of the corresponding output optical signals.

Abstract: An optical sensor comprises an optical element having diffractive elements and a sensing region. The diffractive elements are collectively arranged to comprise spectral and spatial transformation information and to transform an input optical signal into an output optical signal according to the transformation information. The sensing region is arranged for receiving sample material so that the optical signals spatially overlap the sample material in the sensing region. The diffractive element set and the sensing region are arranged so that the spectral or spatial transformation information varies according to an optical property of the sample material. A sensing method comprises: receiving into the sensing region the sample material; receiving into the optical element the input optical signal; and receiving from the optical element the output optical signal. The method may further comprise measuring the variation of the spectral transformation information resulting from the sample substance.

Abstract: A cam assembly for an archery bow comprises: a journal for letting out a draw cable as the bow is drawn and the cam assembly rotates; a take-up mechanism for taking up a first power cable; and a let-out mechanism for letting out a second power cable. A second similar cam assembly comprises: a journal for letting out the draw cable; a take-up mechanism for taking up the second power cable; and a let-out mechanism for letting out the first power cable. Draw force versus draw distance for the bow is at least in part determined by: relative rates of take-up and let-out of the first power cable by the first and second cam assemblies, respectively; and relative rates of take-up and let-out of the second power cable by the second and first cam assemblies, respectively.

Abstract: A method for treating metal-working fluid comprises reducing a concentration in the metal-working fluid of at least one metal by passing the metal-working fluid through an ion-exchange filter. The at least one metal may comprise cobalt or one or more other metal(s). The ion-exchange filter may include an ion-exchange resin, and the resin may comprise a sulfonated divinyl-benzene-cross-linked polystyrene ion-exchange resin. The metal-working fluid may be recirculated through the ion-exchange filter, from a holding vessel, from a sump or reservoir, or from any other container of the metal-working fluid.

Abstract: An optical apparatus comprises a planar optical waveguide having at least two reflectors. The planar optical waveguide substantially confines in at least one transverse spatial dimension optical signals propagating therein, and the reflectors define an optical resonator that supports at least one resonant optical cavity mode. At least one of the reflectors comprises a set of diffractive elements arranged: so that an optical signal in one of the resonant optical cavity modes is successively incident on the diffractive elements; so as to exhibit a positional variation in amplitude, optical separation, or spatial phase; and so as to apply a transfer function to the optical signal successively incident on the diffractive elements. The transfer function is determined at least in part by said positional variation in amplitude, optical separation, or spatial phase exhibited by the diffractive elements.

Abstract: An optical apparatus comprises a planar optical waveguide and at least one set of diffractive elements formed in or on the waveguide. The waveguide is arranged to confine propagating optical signals in at least one transverse dimension. The diffractive element set collectively exhibits a positional variation in diffractive amplitude, optical separation, or spatial phase over some portion of the set. The diffractive element set is collectively arranged to route, as an output optical signal, between corresponding input and output optical ports, a corresponding diffracted portion of an input optical signal. The diffractive element set is collectively arranged so that the input optical signal or the output optical signal is successively incident on the diffractive elements.