Abstract: An optical apparatus comprises a first and second cladding layers and first and second core layers between the cladding layers. The second core has a set of diffractive elements. The first core and the claddings are arranged to form a slab waveguide supporting slab waveguide modes and confining in one transverse dimension optical signals propagating in two dimensions in the slab waveguide modes. The second core and the claddings are arranged to from a channel waveguide supporting one or more channel waveguide optical modes and confining in two transverse dimensions optical signals propagating in one dimension in the channel waveguide modes. The diffractive elements are arranged to couple at least one slab waveguide mode and at least one channel waveguide mode to enable transfer of an optical signal between the slab and channel waveguide optical modes thus coupled.

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 spectral filter comprises a planar optical waveguide having at least one set of diffractive elements. The waveguide confines in one transverse dimension an optical signal propagating in two other dimensions therein. The waveguide supports multiple transverse modes. Each diffractive element set routes, between input and output ports, a diffracted portion of the optical signal propagating in the planar waveguide and diffracted by the diffractive elements. The diffracted portion of the optical signal reaches the output port as a superposition of multiple transverse modes. A multimode optical source may launch the optical signal into the planar waveguide, through the corresponding input optical port, as a superposition of multiple transverse modes. A multimode output waveguide may receive, through the output port, the diffracted portion of the optical signal. Multiple diffractive element sets may route corresponding diffracted portions of optical signal between one or more corresponding input and output ports.

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: A spectral filter comprises a planar optical waveguide having at least one set of diffractive elements. The waveguide confines in one transverse dimension an optical signal propagating in two other dimensions therein. The waveguide supports multiple transverse modes. Each diffractive element set routes, between input and output ports, a diffracted portion of the optical signal propagating in the planar waveguide and diffracted by the diffractive elements. The diffracted portion of the optical signal reaches the output port as a superposition of multiple transverse modes. A multimode optical source may launch the optical signal into the planar waveguide, through the corresponding input optical port, as a superposition of multiple transverse modes. A multimode output waveguide may receive, through the output port, the diffracted portion of the optical signal. Multiple diffractive element sets may route corresponding diffracted portions of optical signal between one or more corresponding input and output ports.

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.

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: 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.

Abstract: An optical waveguide includes a set of diffractive elements. The diffractive element set routes within the waveguide a diffracted portion of an input optical signal between input and output optical ports. The input optical signal is successively incident on the diffractive elements. The optical signal propagates in the waveguide in a corresponding signal optical transverse mode substantially confined in at least one transverse dimension. A modal index of the signal optical mode or a modal index of a loss optical mode spatially varies along a signal propagation direction within the optical waveguide, or the loss optical mode is optically damped as it propagates along the optical waveguide. Said signal modal index variation, said loss modal index variation, or said loss mode damping yields a level of optical coupling between the signal optical mode and the loss optical mode at or below an operationally acceptable level.

Abstract: Method and apparatus are contemplated for receiving from an input, an optical signal in a volume hologram comprising a transfer function that may comprise temporal or spectral information, and spatial transformation information; diffracting the optical signal; and transmitting the diffracted optical signal to an output. A plurality of inputs and outputs may be coupled to the volume hologram. The transformation may be a linear superposition of transforms, with each transform acting on an input signal or on a component of an input signal. Each transform may act to focus one or more input signals to one or more output ports. A volume hologram may be made by various techniques, and from various materials. A transform function may be calculated by simulating the collision of a design input signal with a design output signal.

Abstract: An optical multiplexing device includes an optical element having at least one set of diffractive elements, and an optical reflector. The reflector routes, between first and second optical ports, that portion of an optical signal transmitted by the diffractive element set. The diffractive element set routes, between first and multiplexing optical ports, a portion of the optical signal that is diffracted by the diffractive element set. More complex optical multiplexing functionality(ies) may be achieved using additional sets of diffractive elements, in a common optical element (and possibly overlaid) or in separate optical elements with multiple reflectors. Separate multiplexing devices may be assembled with coupled ports for forming more complex devices. The respective portions of an optical signal transmitted by and reflected/diffracted from the diffractive element set typically differ spectrally.

Abstract: A planar optical waveguide is formed having sets of locking diffractive elements and means for routing optical signals. Lasers are positioned to launch signals into the planar waveguide that are successively incident on elements of the locking diffractive element sets, which route fractions of the signals back to the lasers as locking feedback signals. The routing means route between lasers and output port(s) portions of those fractions of signals transmitted by locking diffractive element sets. Locking diffractive element sets may be formed in channel waveguides formed in the planar waveguide, or in slab waveguide region(s) of the planar waveguide. Multiple routing means may comprise routing diffractive element sets formed in a slab waveguide region of the planar waveguide, or may comprise an arrayed waveguide grating formed in the planar waveguide. The apparatus may comprise a multiple-wavelength optical source.