Abstract: A Fourier transform spectrometer implemented on a photonic integrated circuit (PIC) is provided. An input optical signal waveguide carries an input optical signal to be analyzed to an on-chip Y branch splitter to split the input signal equally to carry coupled-optical signals related to the input optical signal into twin array waveguides of a first waveguide array and a second waveguide array. The optical signal from the first waveguide array and the optical signal from the second waveguide array intersect at a preset intersecting angle at an output plane of the PIC such that the spectral and spatial resolutions of the interferogram of the spectrometer are determined by the intersecting angle.

Abstract: A wavelength-division lightwave multiplexing device, and method of its manufacture, having an embedded filter and two parabola-shaped crossing waveguides, the waveguides providing collimation of light transmitted therein. At least one of the parabola-shaped wave crossing waveguides includes a first port, and a second port, and a widened portion between the first and second ports having a parabola-shaped profile, wherein the widened portion widens from the first port toward a midpoint thereof, and then narrows to the second port. The invention achieves low insertion loss and high spectral isolation while keeping a narrow guard band smaller, and addresses the problem of poor spectral isolation characteristics in the filter-embedded waveguide WDM device when it is adopted to applications requiring a guard band narrower.

Abstract: An apparatus including a transform spectrometer with n×4 multi-mode interface optical hybrid couplers, wherein n=2 or 4, is herein provided. A transform spectrometer apparatus implemented on a planar waveguide circuit is also provided, including: an input optical signal waveguide for carrying an input optical signal; a plurality of input couplers connected to the input optical signal waveguide, each input coupler capable of sending an output signal; an array of interleaved waveguide Mach-Zehner interferometers (MZI), with each MZI coupled to a respective input coupler and each MZI having at least one MZI waveguide for receiving an output signal; and, a plurality of output coupler portions, each output coupler portion coupled to a respective MZI. Each output coupler portion includes one or more inputs along which the output is received from the MZI, and a plurality of outputs for outputting a plurality of signals.

Abstract: Arrayed waveguide grating (AWG) circuits are disclosed, having different radii in the slab regions to supplement and/or replace other mechanical techniques which enable athermal AWGs. Dual band, interleaved pairs of athermal AWGs are also disclosed, with improved cost, space and center wavelength properties, for, e.g., optical line terminal (OLT), and remote node (RN) applications.

Abstract: A transform spectrometer measurement apparatus and method for a planar waveguide circuit (PLC). The spectrometer typically includes an input optical signal waveguide carrying an input optical signal; a plurality of couplers, each connected to the input optical signal waveguide, and each including a coupler output for carrying a coupled optical signal related to the input optical signal; and an array of interleaved, waveguide Mach-Zehnder interferometers (MZI), each having at least one input MZI waveguide, each MZI input waveguide receiving a coupled optical signal from a respective coupler output. A phase shifting circuit is applied to at least one arm of the MZIs to induce an active phase shift on the arm to thereby measure phase error in the MZIs. Light output from the MZIs is measured under intrinsic phase error conditions and after an active phase shift by the phase shifting circuit.

Abstract: A transform spectrometer measurement apparatus and method for a planar waveguide circuit (PLC). The spectrometer typically includes an input optical signal waveguide carrying an input optical signal; a plurality of couplers, each connected to the input optical signal waveguide, and each including a coupler output for carrying a coupled optical signal related to the input optical signal; and an array of interleaved, waveguide Mach-Zehnder interferometers (MZI), each having at least one input MZI waveguide, each MZI input waveguide receiving a coupled optical signal from a respective coupler output. A phase shifting circuit is applied to at least one arm of the MZIs to induce an active phase shift on the arm to thereby measure phase error in the MZIs. Light output from the MZIs is measured under intrinsic phase error conditions and after an active phase shift by the phase shifting circuit.

Abstract: A transform spectrometer implemented on a planar waveguide circuit (PLC), having an input optical signal waveguide carrying an input optical signal to be analyzed; a plurality of couplers, each connected to the input optical signal waveguide, and each including a coupler output for carrying a coupled optical signal related to the input optical signal. An array of interleaved, asymmetrical waveguide Mach-Zehnder interferometers (MZI) is formed on the PLC, each having at least one input MZI waveguide, each MZI input waveguide receiving a coupled optical signal from a respective coupler output; wherein at least some of the input MZI waveguides intersect in a common layer of the PLC, at an angle which allows their respective coupled optical signals to transmit without unacceptable attenuation. This arrangement improves spatial efficiency of the PLC, allowing more MZIs to be implemented, resulting in increased spectral resolution.

Abstract: A silicon photonics array waveguide grating (AWG), and methods of their manufacture, including a plurality of silicon photonics array waveguides running from at least one of an input and output slab waveguide region, wherein first sections of each of the plurality of array waveguides have a first core geometry; and second sections of each of the plurality of array waveguides have a second core geometry. The first and second core geometries may comprise different waveguide core widths, and/or different core structures. AWG temperature stability is provided by the techniques of the present invention.

Abstract: Arrayed waveguide grating (AWG) circuits are disclosed, having different radii in the slab regions to supplement and/or replace other mechanical techniques which enable athermal AWGs. Dual band, interleaved pairs of athermal AWGs are also disclosed, with improved cost, space and center wavelength properties, for, e.g., optical line terminal (OLT), and remote node (RN) applications.

Abstract: A transform spectrometer implemented on a planar waveguide circuit (PLC), having an input optical signal waveguide carrying an input optical signal to be analyzed; a plurality of couplers, each connected to the input optical signal waveguide, and each including a coupler output for carrying a coupled optical signal related to the input optical signal. An array of interleaved, asymmetrical waveguide Mach-Zehnder interferometers (MZI) is formed on the PLC, each having at least one input MZI waveguide, each MZI input waveguide receiving a coupled optical signal from a respective coupler output; wherein at least some of the input MZI waveguides intersect in a common layer of the PLC, at an angle which allows their respective coupled optical signals to transmit without unacceptable attenuation. This arrangement improves spatial efficiency of the PLC, allowing more MZIs to be implemented, resulting in increased spectral resolution.

Abstract: In the disclosed optical signal processing device, the digital-to-analog conversion of the input optical signals is realized in an optical region, without converting the input optical signals into electric signals for the purpose of signal processing, by splitting input optical signals into plural sets, delaying the split optical signals for mutually different delay amounts while adjusting amplitudes of these optical signals, combining these optical signals, and gating these optical signals on a time axis. It is also possible to realize the processing of the optical signals that are multiplexed on a time axis such as interchanges of time-slots similarly.

Abstract: The object of the present invention is to provide a compact dispersion slope equalizer by which it is possible to simultaneously recover distorted waveforms of WDM signals by dispersion slope of DSF or NZ-DSF at 1.55 ?m band, and to compensate for the dispersion of various fiber transmission lines having various dispersion values and variation of dispersion value caused by the temperature change or the like. WDM signals distorted by the dispersion slope of the fiber are introduced into an input waveguide, and are demultiplexed by a wavelength demultiplexer into each wavelength component, and pass through lattice-form optical circuits, transversal-form optical circuits, or the combination of these circuits. The dispersion slope of the signals is compensated for by these circuits. The recovered signals are multiplexed by a wavelength multiplexer, and the multiplexed light is outputted at an output waveguide. Arrayed-waveguide gratings can be used as the wavelength demultiplexer and multiplexer.

Abstract: A matrix switch of an optical waveguide type which has low transmission loss variations and includes uniform grooves with a deep vertical cross section is provided. A switching part for selecting between a light path extending from an input port of a first set of optical waveguides 111-11m to an output port of the first set of optical waveguides 111-11m and a light path extending from an input port of the first set of optical waveguides 111-11m to an output port of a second set of optical waveguides 121-12n is arranged for insertion into a switching groove arranged at each of the intersections of the first set of optical waveguides 111-11m and the second set of optical waveguides 121-12n. Each of the switching grooves is arranged on an imaginary straight line connecting intersections of the first set of optical waveguides 111-11m and the second set of optical waveguides 121-12n.

Abstract: The object of the present invention is to provide a compact dispersion slope equalizer by which it is possible to simultaneously recover distorted waveforms of WDM signals by dispersion slope of DSF or NZ-DSF at 1.55 ?m band, and to compensate for the dispersion of various fiber transmission lines having various dispersion values and variation of dispersion value caused by the temperature change or the like. WDM signals distorted by the dispersion slope of the fiber are introduced into an input waveguide, and are demultiplexed by a wavelength demultiplexer into each wavelength component, and pass through lattice-form optical circuits, transversal-form optical circuits, or the combination of these circuits. The dispersion slope of the signals is compensated for by these circuits. The recovered signals are multiplexed by a wavelength multiplexer, and the multiplexed light is outputted at an output waveguide. Arrayed-waveguide gratings can be used as the wavelength demultiplexer and multiplexer.

Abstract: The object of the present invention is to provide a compact dispersion slope equalizer by which it is possible to simultaneously recover distorted waveforms of WDM signals by dispersion slope of DSF or NZ-DSF at 1.55 ?m band, and to compensate for the dispersion of various fiber transmission lines having various dispersion values and variation of dispersion value caused by the temperature change or the like. WDM signals distorted by the dispersion slope of the fiber are introduced into an input waveguide, and are demultiplexed by a wavelength demultiplexer into each wavelength component, and pass through lattice-form optical circuits, transversal-form optical circuits, or the combination of these circuits. The dispersion slope of the signals is compensated for by these circuits. The recovered signals are multiplexed by a wavelength multiplexer, and the multiplexed light is outputted at an output waveguide. Arrayed-waveguide gratings can be used as the wavelength demultiplexer and multiplexer.

Abstract: An optical multiplexer is equipped with at least one input channel optical waveguide provided on an optical waveguide substrate, a first slab optical waveguide, a channel optical waveguide array formed from a plurality of optical waveguides having a prescribed waveguide length, a second slab optical waveguide and at least one output channel optical waveguide sequentially connected in a tandem arrangement; and phase adjustment to achieve the same phase distribution in the channel optical waveguide array.

Abstract: A polarization maintaining optical fiber is formed by using a core in a cross sectional shape having different diameters along two orthogonal axes defined on a plane perpendicular to an optical axis, or a photonic crystal structure cladding having a diffraction grating with lattice intervals for realizing confinement of lights within the core which are different along two orthogonal axes defined on a plane perpendicular to an optical axis, or the photonic crystal structure cladding that is divided into four divided portions along a circumferential direction, where at least a part of lattice holes in a first pair of divided portions that are facing each other along one direction have a diameter larger than that of lattice holes in a second pair of divided portions that are facing each other along another direction orthogonal to the one direction.

Abstract: A matrix switch of an optical waveguide type which has low transmission loss variations and includes uniform grooves with a deep vertical cross section is provided. A switching part for selecting between a light path extending from an input port of a first set of optical waveguides 111-11m to an output port of the first set of optical waveguides 111-11m and a light path extending from an input port of the first set of optical waveguides 111-11m to an output port of a second set of optical waveguides 121-12n is arranged for insertion into a switching groove arranged at each of the intersections of the first set of optical waveguides 111-11m and the second set of optical waveguides 121-12n. Each of the switching grooves is arranged on an imaginary straight line connecting intersections of the first set of optical waveguides 111-11m and the second set of optical waveguides 121-12n.

Abstract: It is an object of the present invention to provide an optical filter which allows parameters to be easily adjusted, which allows birefringence and temperature dependence to be easily compensated for, and which is essentially free from dispersion. The optical filter includes an optical coupler that splits light into two beams, optical couplers connected to outputs of the optical coupler, a first group of two optical waveguide delay lines connected to the coupler, a second group of two optical waveguide delay lines connected to the coupler, an optical coupler that combines lights from the first group of the lines, an optical coupler that combines lights from the second group of the lines, and a multimode interference optical coupler that combines lights from the couplers together.

Abstract: An optical CDMA encoder-decoder is constructed by combining arrayed-waveguide gratings, matrix optical switches, and delay lines, otherwise by combining arrayed-waveguide grating and variable delay lines, thus providing an encoding process that a wavelength change with respect to time in optical pulses. The light includes a wide spectrum band width inserted into a CDMA encoder/decoder and is demultiplexed by arrayed-waveguide gratings. Each wave length according to the demultiplexed spectrum component spreads out in the time region based on delay time differences produced by delay lines having differential optical lengths. Thus, in CDMA, the dependency of wavelengths on delay time can be set arbitrarily.