Other

Jds Uniphase Corporation

Jds Fitel Inc.

Commissariat a L'energie Atomique

Vincent Delisle

Alan J P Hnatiw

Yihao Cheng

Thomas Ducellier

Neil Teitelbaum

Steven David Oliver

Gary S Duck

Patrick Pouteau

Sheldon McLaughlin

Gonzalo Wills

Gilles Grand

Pierre D Wall

Michel A Duguay

Dean Sheldon Spicer

Udo Trutschel

Uwe Langbein

Dominique Brichard

The present invention relates to an optical filter comprising an integrated wavelength dispersive element having an input for providing temperature compensation, particularly for providing passive temperature compensation in an arrayed waveguide grating. The present invention has found that by providing an arrayed waveguide grating having a thermally responsive pivotal input structure for changing an angle of a collimated input signal launched into a focusing lens, the input point can be selected in response to changing temperature in order to compensate for thermal drift of the center wavelength. Further, the present invention has found that by providing a reflective lens assembly for focusing an input signal at a selected input point of the input planar waveguide, alignment and tuning of an input and assembly can be improved and simplified. As an additional advantage, variable coupling parameters can be incorporated into a reflective coupling including input position, waveguide taper and planar waveguide length increment to provide relatively simple tuning in an integrated device.

Method and apparatus for reducing the wavelength dependency of an integrated optical filter

This invention relates to elements such as birefringent crystals, which are used to separate a non-collimated input beam into two orthogonally polarized sub-beams or to combine two orthogonally polarized beams into a single beam. The optical device lessens or obviates the optical path length difference encountered in prior art devices and provides a polarization beam splitter/combiner that has substantially same optical path lengths for two split or combined beams propagating therethrough. Alternatively, the device is designed to provide a selected path length difference to compensate for polarization mode dispersion in other optical devices. The polarization beam splitter/combiner in accordance with the invention has a first uniaxial crystal having an o-ray path and an e-ray path and having the first port disposed at an end face thereof; a second uniaxial crystal having an o-ray path and an e-ray path, the e-ray path of the second uniaxial crystal being optically coupled with the o-ray path of the first uniaxial crystal and the o-ray path of the second uniaxial crystal being optically coupled with the e-ray path of the first uniaxial crystal. Alternatively, the axis of the second crystal is aligned in such a manner that the o-ray path is retarded by an extraordinary index of refraction of the crystal and the e-ray path is retarded by an ordinary index of refraction to equalize the optical path lengths.

Polarization beam splitter or combiner

The present invention relates to an arrayed waveguide grating having a reflective input that permits variable coupling to adjust the center wavelength. The present invention has found that by providing an arrayed waveguide grating having one or more precisely positioned input waveguides coupled through a reflective lens assembly, for providing a lateral offset to a signal propagating from the input waveguide to the planar waveguide, and for focusing a reflected input signal at a selected input point of the input planar waveguide, alignment and tuning of an input and assembly can be improved and simplified. Advantageously, variable coupling parameters can be incorporated into the reflective coupling including input position, waveguide taper and planar waveguide length increment to provide relatively simple tuning in an integrated device. Compensation for polarization effects and thermal effects can also be provided in the reflective coupling.

Arrayed waveguide grating having a reflective input coupling

The invention disclosed relates to a device for multiplexing/demultiplexing a multi-band DWDM system, providing reduced insertion losses. The device comprises first and second planar waveguides, a light dispersive element having a periodic frequency spectrum, interconnecting the first and second planar waveguides, a plurality of N input waveguides, connected to the first planar waveguide, and a plurality of M output waveguides, connected to the second planar waveguide, wherein the M outputs are each separated by a frequency interval &Dgr;f, the N inputs are each separated by substantially M*&Dgr;f, the free spectral range (FSR) equals substantially N*M*&Dgr;f, where N is an integer greater than 1, and M is an integer equal to or greater than N. In one embodiment of the invention, wherein the telecommunications window is divided into a plurality of sub-bands of M channels, a temperature controller is included to provide individual temperature set points for each sub-band, to reduce wavelength centering errors.

Periodic arrayed waveguide grating multiplexer/demultiplexer

A multiplexing/demultiplexing optical circuit provides a demultiplexed output spectrum of channels having a flat amplitude response without sacrificing optical power. A phased array implementation and a diffraction grating implementation both rely on a first dispersion of the beam to be demultiplexed and subsequent division of the wavelengths into channels. Local inversion is induced within each channel of the dispersed wavelengths about a channel central wavelength. After the wavelengths are spatially inverted, they are once again provided to a dispersion element or array effectively nullifying the dispersion effects across the channel band to provide output channels having a substantially &ldquo;flat-tops&rdquo;, while providing good channel separation through global dispersion of all the wavelengths.

Multiplexors with a flat top spectral channel shape

This invention relates generally to custom optical filters such as filters relating to, flat-top WDM multiplexer/demultiplexers, flat-top and peaky comb filters or reconfigurable add & drop filters. The embodiment disclosed below is based on mid-dispersion wavelength bands processing, wherein the optical spectrum is dispersed in two steps; in-between these two steps, the wavelength bands are manipulated in the focal plane, for example by being moved, reflected, absorbed, inverted, magnified or reduced to achieve a particular result. A masked mirror or masked transmissive element selects wavelength by position. The mask shape for relatively complex filtering functions is much simpler than currently used for collimated beams because of the correlation between position and wavelength. Inversion of channel bands or movement of channel bands in two dimensions in the focal plane, in particular, enables the construction of numerous useful devices. It is possible to realize custom flat-top optical filters, custom shaped optical filters, flat-top WDM multiplexer/demultiplexers, flat-top and peaky comb filters or reconfigurable add & drop filters.

Custom optical filters

This device comprises a planar input area (,), a planar output area (,), a microguides array (,) laid out between these areas, means (,) of inputting a light beam associated with the input area and means (,) of outputting a light beam associated with the output area. According to the invention, at least two pieces (,) are formed, one comprising one part of at least one of the areas and the corresponding associated means, the other comprising the other part of this area and the other components of the device, and the pieces are added on so as to form the complete device and to adjust the wave length of this device. Application to optical telecommunications and optical spectrometry.

Phased array device or phasar and process for manufacturing this device

The optical device provides dispersion adjustment or compensation using resonant coupling between a first waveguide and a second waveguide which has a variable thickness and a significantly different index of refraction. The two waveguides are optically coupled about a lateral coupling surface, and as light propagates down the waveguide, it passes from one waveguide to the other at a predetermined position along the propagation axis depending on the thickness of the second waveguide. Mode converters are used at the input and output of the device to provide for more efficient operation. The first waveguide can be made of silica and the second waveguide of silicon, thus providing a differential in the index of refraction of about 2. For dispersion compensation, in which shorter wavelengths need to be retarded with respect to longer wavelengths, the profile of the thickness of the second waveguide is such that shorter wavelengths spend more time in the silicon than do longer wavelengths. The shorter wavelength components are thus slowed down more than the longer wavelength components in the optical communications signal.

Tapered waveguide for optical dispersion compensation

A useful device is provided for coupling or splitting optical signals from one port to another. The symmetry of a lens is utilized in a manner whereby two linear arrays of optical ports are disposed adjacent the optical axis of the lens equidistant from the optical axis of the lens. An at least partially reflecting optical element is disposed at a collimating end of the lens. Signals launched into one array of ports reflects back to the second array of ports at the same end. In another embodiment of the invention utilizing these two linear arrays of waveguides, two matched lenses having an element disposed between are used as a coupler/splitter. In this arrangement ports are positioned on opposite sides of the optical axis equidistant from it.

Multi-port fiber optical device

An optical device comprising a planar waveguide, and a second portion spaced from the planar waveguide portion by a gap to receive optical signals therefrom, the planar waveguide portion including: means integrated therein for separating an input beam into sub-beams having different central wavelengths; the second portion having closely spaced waveguides for receiving the sub-beams of light and having passive temperature compensation means coupled therewith for enhancing the coupling of the optical signals having predetermined wavelengths provided by the first block with the closely spaced waveguides.

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Ottawa, Canada

Vincent Delisle