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:
A diffraction grating comprises a substrate with a set of protruding ridges and intervening trenches characterized by a ridge spacing Λ, 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, λ/2n1
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. The portion reflected from the diffractive element set may comprise one or more channels of an optical WDM system.
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 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.
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 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:
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:
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 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:
A reconfigurable add-drop multiplexer (R-OADM) comprises an array of channel waveguides coupling two groups of diffractive element sets on a slab waveguide. The channel waveguides include switchable reflectors or are coupled to other channel waveguides by optical switches. Switching a reflector to reflect or setting a switch to couple two waveguides results in a corresponding wavelength channel being added or dropped. Switching the reflector to transmit or setting the switch to uncouple the two waveguides allows the corresponding wavelength channel to pass through the R-OADM without being added or dropped.