Abstract: A method for improving surface accuracy of an optical component comprises: positioning a first surface of the optical component against a reference surface of a reference member; urging together the reference member and the optical component; adhering a second surface of the optical component to a first surface of a support member; and separating the reference member from the optical component while leaving the optical component adhered to the support member. Urging together the reference member and the optical component substantially conforms the surface accuracy of the first surface of the optical component to the surface accuracy of the reference surface of the reference member. Adhering the optical component to the support member and then separating the reference member from the optical component leaves the surface accuracy of the first surface of the optical component substantially in conformance with the surface accuracy of the first surface of the reference member.

Abstract: An optical diffraction grating includes a substantially transparent grating substrate which has substantially flat first and second surfaces, and a set of grating lines on the first surface characterized by a grating spacing ?. The grating substrate has a temperature-dependent refractive index nsub and is immersed in a medium having a temperature-dependent refractive index nmed. The first and second substrate surfaces are non-parallel and form a dihedral angle ?. The gratings lines are substantially perpendicular to a plane of incidence defined by surface-normal vectors of the first and second surfaces. Variation of a diffraction angle ?d? with temperature, exhibited by the optical diffraction grating at a design wavelength ? and at a design incidence angle ?in in the plane of incidence, is less than that variation exhibited by a reference diffraction grating that has parallel first and second substrate surfaces but is otherwise identical to the optical diffraction grating.

Abstract: A diffraction grating comprises a substrate with a set of protruding ridges and intervening trenches characterized by a ridge spacing ?, width d, and height h. The substrate comprises a dielectric or semiconductor material with a refractive index n1; the first substrate surface faces an optical medium with a refractive index n2 that is less than n1. Each ridge has a metal layer on its top surface of thickness t; at least a portion of the bottom surface of each trench is substantially free of metal. Over an operational wavelength range, ?/2n1<?<?/(n1+n2) can be satisfied. An optical signal can be incident on the diffractive elements from within the substrate at an incidence angle that exceeds the critical angle. The parameters n1, n2, ?, d, h, and t can be selected to yield desired polarization dependence or independence of the diffraction efficiency.

Abstract: An optical grating comprising a grating layer and two surface layers, the layers being arranged with the grating layer between the surface layers. The grating layer comprises a set of multiple, discrete, elongated first grating regions that comprise a first dielectric material and are arranged with intervening elongated second grating regions. The bulk refractive index of the dielectric material of the first grating regions is larger than the bulk refractive index of the second grating regions. The first surface layer comprises a first impedance matching layer, and the second surface layer comprises either (i) a second impedance matching layer or (ii) a reflective layer. Each said impedance matching layer is arranged to reduce reflection of an optical signal transmitted through the corresponding surface of the grating layer, relative to reflection of the optical signal in the absence of said impedance matching layer.

Abstract: A diffraction grating comprises a substrate with a set of protruding ridges and intervening trenches characterized by a ridge spacing ?, width d, and height h. The substrate comprises a dielectric or semiconductor material with a refractive index n1; the first substrate surface faces an optical medium with a refractive index n2 that is less than n1. Each ridge has a metal layer on its top surface of thickness t; at least a portion of the bottom surface of each trench is substantially free of metal. Over an operational wavelength range, ?/2n1<?<?/(n1+n2) can be satisfied. An optical signal can be incident on the diffractive elements from within the substrate at an incidence angle that exceeds the critical angle. The parameters n1, n2, ?, d, h, and t can be selected to yield desired polarization dependence or independence of the diffraction efficiency.

Abstract: A flat substrate bears a set of flat, coplanar diffraction gratings; a jewelry mounting is secured to the substrate. The gratings are arranged to occupy corresponding areas of the substrate that are arranged to correspond to a two-dimensional projection of multiple, non-coplanar facets of a three-dimensional gemstone. Each grating differs from one or more other gratings with respect to grating wavevector direction so that each grating differs from at least one other grating with respect to direction of dispersion of spectrally dispersed output directions of a diffracted portion of light incident on the gratings along a given input direction. The grating wavevectors are spatially distributed among the corresponding gratings to form two or more subsets of three or more gratings along which subsets the corresponding grating wavevector direction of each grating of the subset varies monotonically with position of that grating along a given dimension of the substrate.

Abstract: A first article has a surface bearing a diffraction grating that comprises a plurality of elevated regions and recessed regions and a reflective coating that provides reflective diffraction within the article but is sufficiently thick to prevent diffraction outside the article. Alternatively, the reflective coating can be arranged to also provide reflective diffraction outside the article. A second article has a surface bearing a diffraction grating that comprises a plurality of elevated regions and recessed regions. Either (i) at least a portion of each ridge, or (ii) at least portion of each trench, comprises a material differing with respect to its refractive index or with respect to its optical transmissivity.

Abstract: A packaging article comprises first and second packaging members with one or more depressions and corresponding protrusions, respectively, and can be assembled with their each protrusion received within the corresponding depression. A transverse cross section of each depression is concave. A transverse cross section of each protrusion includes a secondary protrusion that forms a longitudinal ridge; a longitudinal cross section of the ridge comprises one or more concavities. A substantially rectangular object is place in a depression and the first and second packaging members are assembled. The object, received within the depression and located between the assembled packaging members, rests with two opposing edges of the object urged against the concave surface of the depression with corresponding lines of contact oriented substantially longitudinally, and with two other opposing edges of the object urged against the concavity.

Abstract: An article comprises a volume of material having at least one faceted or curved surface, and at least one diffraction grating on at least one surface of the article. The diffraction grating comprises a set of diffractive elements formed in a deformable layer attached to the surface of the article. A method comprises forming the set of diffractive elements by deformation of the deformable layer, and attaching the deformable layer to a surface of the article. The layer can be deformed to form the diffractive elements before or after it is attached to the surface of the article.

Abstract: An optical apparatus comprises at least one primary diffraction grating and at least one reference diffraction grating each formed on or within a common grating substrate. The reference diffraction grating is arranged so as to diffract and disperse spatially according to wavelength a reference optical signal incident on the reference diffraction grating at an input incidence angle. The primary diffraction grating is arranged so as to diffract and disperse spatially according to wavelength an input optical signal incident on the primary diffraction grating at the input incidence angle. The reference and primary diffraction gratings exhibit at least one differing grating structural parameter. The reference and primary diffraction gratings are arranged so that a diffracted and spatially dispersed reference optical signal having at least one known wavelength component defines at least one spatial wavelength calibration reference for the diffracted and spatially dispersed input optical signal.

Abstract: An optical grating comprising a grating layer and two surface layers, the layers being arranged with the grating layer between the surface layers. The grating layer comprises a set of multiple, discrete, elongated first grating regions that comprise a first dielectric material and are arranged with intervening elongated second grating regions. The bulk refractive index of the dielectric material of the first grating regions is larger than the bulk refractive index of the second grating regions. The first surface layer comprises a first impedance matching layer, and the second surface layer comprises either (i) a second impedance matching layer or (ii) a reflective layer. Each said impedance matching layer is arranged to reduce reflection of an optical signal transmitted through the corresponding surface of the grating layer, relative to reflection of the optical signal in the absence of said impedance matching layer.

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 optical apparatus comprises a set of diffractive elements on a substrate. They are arranged: (i) to receive an input signal propagating from an input port as a diffraction-guided optical beam, (ii) to diffract a portion of the received input signal as an output signal, (iii) to route the output signal to propagate to an output port as a diffraction-guided optical beam, and (iv) to exhibit a positional variation in diffractive amplitude, optical separation, or spatial phase over some portion of the set. The arrangement of the diffractive elements corresponds to an interference pattern derived from computed interference at a surface of the substrate between a simulated design input and output optical signals. Each diffractive element comprises at least one trench segment positioned along a path defined by a constant-phase contour of the interference pattern. Each trench segment is substantially rectangular or trapezoidal in transverse cross section.

Abstract: An optical apparatus comprises a set of diffractive elements (trenches between ribs) arranged on a substrate to: receive a diffraction-guided input optical signal from an input port; diffract the input signal as a diffraction-guided output optical signal; and route the output signal to an output port. In one embodiment, a side surface of each trench is perpendicular to its bottom surface and at least one trench depth is equal to half of its width divided by the tangent of a selected Littrow angle. In another embodiment, a side surface of each rib and its bottom surface are arranged to successively reflect a portion of the input optical signal preferentially in a selected output direction. In another embodiment, each diffractive element comprises multiple trenches; selected relative widths or depths of the multiple trenches of each diffractive element at least partly determining diffractive amplitude and a selected blaze direction.

Abstract: An optical data storage medium comprises an optical medium with multiple data marks. Each data mark is arranged for modifying a portion of an optical reading beam incident thereon. At least one of the data marks is a delocalized data mark comprising a set of multiple diffractive elements collectively arranged for modifying a portion of the optical reading beam incident thereon. A method for recording data on an optical data storage medium comprises forming on or in the optical medium multiple data marks encoding the recorded data, including the at least one delocalized data mark. A method for reading an optical data storage medium comprises: successively illuminating with the optical reading beam the multiple data marks; sensing variations among the respective portions of the optical reading beam modified by the multiple data marks; and decoding from the sensed variations data encoded by the multiple data marks.

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: 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: 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: 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.