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: 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 slab optical waveguide confines in one transverse dimension optical signals propagating in two dimensions therein, and has a set of diffractive elements collectively arranged so as to exhibit positional variation in amplitude, optical separation, or spatial phase. The diffractive elements are collectively arranged so as to apply a transfer function to an input optical signal to produce an output optical signal. The transfer function is determined at least in part by said positional variation in amplitude, optical separation, or spatial phase. The waveguide and diffractive elements are arranged so as to confine only one of the input and output optical signals to propagate in the waveguide so that the optical signal thus confined is successively incident on the 11 diffractive elements, while the other optical signal propagates unconfined by the waveguide in a direction having a substantial component along the confined dimension of the waveguide.

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 distributed optical structure comprises a set of diffractive elements. Individual diffractive element transfer functions collectively yield an overall transfer function between entrance and exit ports. Diffractive elements are defined relative to virtual contours and include diffracting region(s) altered to diffract, reflect, and/or scatter incident optical fields (altered index, surface, etc). Element and/or overall set transfer functions (amplitude and/or phase) are determined by: longitudinal and/or angular displacement of diffracting region(s) relative to a virtual contour (facet-displacement grayscale); longitudinal displacement of diffractive elements relative to a virtual contour (element-displacement grayscale); and/or virtual contour(s) lacking a diffractive element (proportional-line-density gray scale).

Abstract: A method comprises: formulating simulated design input and output optical signals propagating from/to respective designed optical input and output ports as optical beams substantially confined by a planar optical waveguide; computing an interference pattern between the simulated input and output signals; and computationally deriving an arrangement of diffractive elements of a diffractive element set from the computed interference pattern. When the diffractive element set is formed in the planar optical waveguide, each diffractive element routes, between corresponding input and output optical 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: An optical apparatus comprises an optical element having at least two sets of diffractive elements, each diffractive element comprising at least one diffracting region thereof. At least one diffractive element set collectively routes, between a corresponding input optical port and a corresponding output optical port, at least a portion of a corresponding optical signal incident on the diffracting regions that is diffracted thereby as it propagates from the corresponding input optical port. The optical element includes at least one spatial region thereof wherein multiple diffracting regions of a first diffractive element set are present and diffracting regions of a second diffractive element set are absent. The diffractive elements of each set, the diffracting regions thereof, and each said spatial region are arranged so as to impart desired spatial characteristics, desired spectral characteristics, or desired temporal characteristics onto the corresponding routed portion of the optical signal.

Abstract: A distributed optical structure comprises a set of diffractive elements. Individual diffractive element transfer functions collectively yield an overall transfer function between entrance and exit ports. Diffractive elements are defined relative to virtual contours and include diffracting region(s) altered to diffract, reflect, and/or scatter incident optical fields (altered index, surface, etc). Element and/or overall set transfer functions (amplitude and/or phase) are determined by: longitudinal and/or angular displacement of diffracting region(s) relative to a virtual contour (facet-displacement grayscale); longitudinal displacement of diffractive elements relative to a virtual contour (element-displacement grayscale); and/or virtual contour(s) lacking a diffractive element (proportional-line-density gray scale).

Abstract: An optical apparatus comprises an optical element having at least one set of diffractive elements and multiple channel optical waveguides. Diffractive elements of each set are distributed among diffractive element subsets corresponding to each of the multiple channel waveguides. Each diffractive element set routes, between a corresponding pair of optical ports, those corresponding portions of an optical signal propagating within the optical element that are received by multiple channel waveguides and back-diffracted within the receiving channel waveguides by corresponding diffractive element subsets. The channel optical waveguides are arranged so that optical signals propagate through regions of the optical element between the ports and the first ends of the channel waveguides.

Abstract: An optical apparatus comprises a planar optical waveguide having at least one set of diffractive elements and confining in at least one transverse spatial dimension optical signals propagating therein. Each diffractive element set routes, between corresponding input and output optical ports, a corresponding diffracted portion of an input optical signal propagating in the waveguide that is successively incident on the diffractive elements and is diffracted by the diffractive element set. The optical signals propagate in the waveguide in corresponding diffractive-region optical transverse modes in regions where the diffractive elements are present, and in corresponding non-diffractive-region optical transverse modes in regions where the diffractive elements are absent.

Abstract: An apparatus comprises: a planar optical waveguide having sets of locking diffractive elements and means for routing optical signals; and corresponding lasers. Lasers 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.

Abstract: A method and apparatus for laser frequency stabilization and precise laser frequency tuning comprises splitting a laser beam into two beam portions and recombining the two portions after they traverse differing optical distances. The thus-processed combined beam exhibits a time variation in intensity, the time variation being a function of the time rate of change of the laser beam. A signal proportional to the laser frequency's time rate of change is derived from the time variation of the processed beam's intensity and used to generate a control signal to provide feedback to control the laser frequency, thereby providing for laser frequency stabilization. Precise laser frequency tuning may be achieved by introducing a controlled variation in the derived signal, such as by adjusting a frequency differential introduced between the beam portions, or by otherwise introducing a controlled variation in the signal derived from the processed beam.

Abstract: A method of producing at least one filter skein for cigarettes and other smokable rod-shaped articles, from at least one filter tow strip comprises the steps of: (a) drawing at least one filter tow strip, from at least one supply, (b) feeding the at least one filter tow strip to a treatment in a treatment unit; (b1) at the beginning of the treatment unit, subjecting at least one filter strip to a brake force to adjust at least the quantity to be processed, the brake force being set automatically, and (b2) afterwards, stretching and fluffing the filter tow strip(s) by the use of two pairs of rolls, wherein the surface of one roll of at least one pair of the two pairs is smooth and the other roll is profiled over its entire surface, (c) after the treatment, collecting the treated filter tow strip from step (b) in a formating unit to at least one round skein with an enveloping material to form at least one continuous, wrapped filter skein, (d) detecting and measuring a characteristic value of the produced filter

Abstract: An apparatus (10) for holding a collecting container (20) of low stiffness for collecting and packaging re-usable packages for filter tow, has erectable side parts (1) to (6), fastening strips (30) connected with the side parts (1 to 6) for fastening the collecting container (20) on the erected side parts (1 to 6); the side parts (1, 2, 6; 3, 4, 5) are divided into two groups (A) and (B) with the side parts (1, 2, 6) and (3, 4, 5) in each of the groups (A),(B) connected so as to be hinged, and the side parts (1, 2, 6) and (3, 4, 5) in the groups (A),(B) are connected so as to be hinged. The side parts (2, 3) and (5, 6) of the groups (A),(B) are foldable toward the outside away from the collecting container (20) so that the collecting container (20) can be removed from the apparatus (10) laterally or at the front face.

Abstract: A method for producing at least one fiber skein for the production of filters for cigarettes and for other smokable rod-shaped articles, comprises the steps of drawing from a supply at least one filter tow strip, supplying the drawn fiber strip to a subsequent treatment, in which the fiber strip is stretched and fluffed, then the treated fiber strip is collected in a formating unit to a fiber skein which is finally provided with an enveloping material, to form a continuous, wrapped fiber skein. The fiber strip of strips are exposed at the beginning of the treatment to a brake force, to adjust at least the quantity to be processed of the fiber strip of strips, the brake force being set automatically.