534 results about "Waveguide grating" patented technology

Methods of detecting one or more parameters of a medium are disclosed. The methods include providing a waveguide grating device, contacting the waveguide grating with a medium, propagating a signal having at least one signal attribute through the waveguide, and comparing the modified signal attribute to a known signal attribute to detect a parameter of the medium.

An optical waveguide comprises at least two TIR surface and contains a grating. Input TIR light with a first angular range along a first propagation direction undergoes at least two diffractions at the grating. Each diffraction directs light into a unique TIR angular range along a second propagation direction.

An optical coherent detector that employs an interleave-chirped arrayed waveguide grating (AWG). The AWG has a periodic chirp pattern that enables the AWG to function as an optical 90-degree hybrid. If the AWG is implemented using a birefringent material, then the AWG can also function as a polarization demultiplexer. In one embodiment, the AWG is designed to simultaneously function as a wavelength demultiplexer, a polarization demultiplexer for each wavelength-division-multiplexed (WDM) signal component, and a 90-degree hybrid for each polarization-division-multiplexed component of each WDM signal component.

A VCSEL waveguide grating coupler is provided such that a first and second mirror are positioned to define a resonant cavity between them. The waveguide grating coupler further includes a waveguide having a first grating formed as a part of the waveguide to couple light of a first polarization mode into the waveguide. A second grating is formed on the waveguide grating coupler and is orthogonal to the first grating. The second grating is operative to enhance the light coupled to the waveguide by creating a loss difference between light of the first polarization mode and light of a second polarization mode, so that light of the first polarization mode lases preferentially within the VCSEL.

An optical waveguide grating coupler for coupling light between a planar waveguide and an optical element such as an optical fiber. The optical waveguide grating coupler includes a grating comprising a plurality of elongate scattering elements. The optical waveguide grating coupler is preferably flared, and in various embodiments has hyperbolically shaped sidewalls. The elongate scattering elements are preferably curved, and in some embodiments, the scattering elements have elliptically curved shapes. Preferably, the elongated scattering elements have grating widths selected to accommodate the desired optical intensity distribution.

A group of waveguide grating couplers is disposed on a semiconductor substrate. The grating couplers are all within a spot illuminated on the substrate by a light from an optical fiber. The light propagating in the fiber is wavelength division multiplexed (WDM) and consists of several channels. Within the group of grating couplers, at least one grating coupler is designed to be tuned to each of the channels. The group of grating couplers demultiplexes the channels propagating in the fiber. A group of waveguide grating couplers can also be used to multiplex several channels of light into an optical fiber. Single mode and multimode fiber can be used to carry the multiplexed channels of light in an optical multiplexing and demultiplexing system.

The present invention is directed to the provision of a wavelength division multiplexing optical transmission apparatus and, more particularly, to a wavelength division multiplexing optical transmission apparatus having high wavelength stability unaffected by the temperature characteristics, aging, etc. of an arrayed-waveguide grating (AWG) and its peripheral components. The wavelength division multiplexing optical transmission apparatus comprises: an arrayed-waveguide grating 10 having operating input/output ports and an input dummy port; a light emitting means 21 for generating a pilot signal to be input to the input dummy port; a light detecting means 22 for monitoring the pilot signal contained in a wavelength division multiplexed signal output from the operating output port; and a temperature control circuit 11 for controlling the temperature of the arrayed-waveguide grating in such a manner as to cancel the amount of wavelength fluctuation occurring in the arrayed-waveguide grating and detected by monitoring the pilot signal.

Various configurations of elongate scattering elements in an optical waveguide grating coupler for coupling light between a planar waveguide and an optical element such as an optical fiber, where the light may have a Gaussian intensity distribution. The elongate scattering elements are preferably curved, and in some embodiments, the scattering elements have elliptically curved shape. One or more of the elongate scattering elements may be segmented into various geometrical shapes, such as rectangular, square, circular and elliptical. The elongate scattering elements have at least one characteristic selected from the group consisting of grating width, height, spacing, depth and index of refraction forming the elongate scattering elements, where the magnitude of the at least one characteristic varies irregularly with position along the guiding portion of the optical waveguide grating coupler.

In a Wavelength Division Multiplexed Passive Optical Network (WDM-PON) including, a system for distributing uplink, downlink and RF/Video broadcast signalling. An Array Waveguide Grating (AWG) couples respective wavelength channels between a trunk fibre of the WDM-PON and a plurality of branch fibers of the WDM-PON. The AWG has a predetermined free spectral range and implements a channel plan comprising at least three spectral segments, each segment having a width equal to the free spectral range of the AWG. An Optical Line Terminal of the WDM-PON receives wavelength division multiplexed uplink signals within a first one of the spectral segments, and transmits wavelength division multiplexed downlink signals within a second one of the spectral segments. Respective channel plans within the first and second spectral segments are identical. An RF/Video broadcast transmitter generates an RF/Video broadcast signal within a third one of the spectral segments.

A method of simultaneously defining a waveguide and grating in a sample of photosensitive material comprises providing a sample of material (24) having a region which is photosensitive to light of a specific wavelength, generating a spot of light (22) at the specific wavelength, the spot having a periodic intensity pattern of high and low intensity fringes, and a width which is related to the width of the channel, positioning the spot within the photosensitive region and causing relative movement between the sample and the light spot along the desired path of the waveguide/grating define a channel of altered refractive index by exposing parts of the photosensitive region to the light spot. Modulation of the light spot to produce multiple exposures produces a grating, while continuous exposure results in a uniform waveguide. These structures can be written in straight lines or around curves, and can be accurately overwritten, so that complex optical devices can be produced in a single fabrication step.

The invention discloses a packaging method for high-efficiency vertical coupling interconnection of optical fiber and optical waveguide chip which comprises the following steps of: preparing a silica-based nano waveguide grating and scanning the silica-based nano waveguide grating by applying a scanning electron microscope; preparing a curing packaging material with a low refractive index; preparing a monomode optical fiber; coating an optical anti-reflection film on the surface of the silica-based nano waveguide grating; regulating the position between the monomode optical fiber and the silica-based nano waveguide grating; dispensing an adhesive at the coupling ends of the monomode optical fiber and the silica-based nano waveguide grating; exposing and curing an inner packaged body subjected to adhesive dispensing; preparing a V-shaped optical fiber positioning groove; placing the monomode optical fiber in the V-shaped optical fiber positioning groove; carrying out curing packaging on the monomode optical fiber; exposing and curing the V-shaped optical fiber positioning groove subjected to adhesive dispensing; and testing the finally packaged structure. The invention overcomes the defects of instability and the like of a nano waveguide and grating vertical coupling system on the existing optical integrated chip. The packaged structure provided by the invention has simple structure and high stability, resists external interference and is easy for array integration.

A variable-reflective tunable optical filter includes an interferometer adapted to control the powers of added or dropped signals and an optical waveguide grating to select the wavelength channels of the added or dropped signals. The waveguide grating is tunable to filter a dropped signal from an input data stream and filter an added signal into an output data stream. While a reflection band of the waveguide grating is being adjusted to tune a wavelength channel, the phase of at least one leg of the interferometer may be adjusted to direct signals of any wavelength channel selected by said waveguide from the input data stream to the output data stream, thereby providing hitless optical add-drop multiplexing.

An arrayed waveguide grating type optical multiplexer and demultiplexer which reduces a package size although plural arrayed waveguide gratings are included, is provided, comprising plural arrayed waveguide gratings which are provided in parallel to one another on a substrate and each of which has a first waveguide, a first slab waveguide, an arrayed waveguide, a second slab waveguide, and a second waveguide, and also includes a waveguide chip divided into a first and second separated waveguide chip in the first or second slab waveguide in each of the arrayed waveguide gratings and a compensation member compensating a temperature dependent shift of a light transmission center wavelength in the arrayed waveguide grating by relatively moving the first and second waveguide chip when expanded or contracted according to a temperature change. The waveguide chip has a shape bending along a bending direction of the arrayed waveguide.

An optical waveguide grating is formed in an optical waveguide core and/or in an optical waveguide cladding where an electric filed of light propagating in the core is spreading by implanting accelerated ions through a mask to the optical waveguide. The mask has enough thickness to prevent the ions irradiated to the masked parts from reaching the portion where the grating is formed. The acceleration energy of the ions is chosen to make the lateral straggling of the implanted ions in the optical waveguide less than three fourths of the period of the grating, or the acceleration energy is chosen to make all or a part of the implanted ions pass through the portion where the grating is formed.

An economical wavelength-division-multiplexed passive optical network (WDM-PON) system is realized by directly modulating a wavelength-seeded light source to transmit upstream or downstream data, without using an expensive external modulator. A multiplexed signal having the same wavelength as the waveguide grating is generated and used to control the temperature of the waveguide grating and adjust the wavelength of a wavelength-division-multiplexed signal routed to a transfer link. The wavelength selectivity and stabilization of each light source are not required. Since upstream and downstream signals can be multiplexed and demultiplexed concurrently by each waveguide grating located in the central office and the remote node, it is possible to reduce the number of waveguide gratings used in a WDM optical network. In addition, upstream and downstream signals can be transmitted concurrently using a single-strand transfer optical fiber, thereby realizing an economical and efficient WDM-PON.

A Wavelength Division Multiplexed Passive Optical Network (WDM-PON) includes an Optical Line Terminal (OLT) including a first Arrayed Waveguide Grating (AWG) MUX/DEMUX, and a remote node including a second AWG MUX/DEMUX. Each AWG MUX/DEMUX has at least two input ports for receiving a respective wavelength division multiplexed optical signal, and a plurality of output ports. Each output port of the Optical Line Terminal AWG MUX/DEMUX is coupled to a respective transceiver of the OLT. Each output port of the remote node AWG MUX/DEMUX is coupled to a respective PON having at least one optical network terminal (ONT). Respective first and second optical paths are coupled between corresponding input ports of the first and second AWG MUX/DEMUXs. Means are provided for sourcing seed light of the WDM-PON into a selected one the first and second optical paths.