Jds Uniphase Corporation

Jds Fitel Inc.

Nigel Copner

Adam D Cohen

Mark Farries

Rajiv Iyer

Barrie P Keyworth

Kim Leong Tan

Reza Paiam

Christopher John Abraham

Thomas Ducellier

Frank Faqiu Liang

Robert Maaskant

Keith Beckley

A Tino Alavie

Feliks Lapinski

Marie Josee Picard

An apparatus is described for controlling the optical path length in an optical device, e.g. an interferometer, and more importantly to maintaining the optical path length difference in an interferometer. The apparatus may include an adjustable plate optically coupled with a beamsplitter. The plate may be rotated such that its surface receives light propagated from the beamsplitter at a non-zero incident angle. In one embodiment, temperature sensitivity is addressed by ensuring that the refractive index of the plate is greater than the refractive index of the beamsplitter. In another embodiment, the apparatus includes combination spacers having a component selected in dependence upon a composition, thickness, and orientation of the adjustable plate.

Athermal interferometer

The present invention relates to an interferometer useful in the interleaving and de-interleaving of optical wavelength channels. Typically the invention comprises a beamsplitter and two resonators, e.g. GT etalons or ring resonators. The beamsplitter splits an input beam of light into a first sub-beam directed to follow a first path and a second sub-beam directed to follow a second path. The first resonator has a first effective cavity length and receives the first sub-beam. The second resonator has a second effective cavity length and receives the second sub-beam. The first path and the second path have an effective optical path difference approximately equal to one-half the first effective cavity length. In one embodiment, the front plates of the GT etalons each have a different reflectivity, and are selected to provide a desired spectral response. In another embodiment, the two resonators are slightly de-phased from one another such that the positive dispersion slope of the first resonator is aligned with the negative dispersion slope of the second resonator. Polarization-based versions of the invention are disclosed, in which a single resonator receives both sub-beams, which are orthogonally polarized. Single etalon versions of the invention are also possible, in which a beam is separated into sub-beams (i.e. reflected and transmitted beams) within a non-linear interferometer, and then re-combined outside the interferometer with the appropriate effective optical path length delay therebetween.

Low dispersion interleaver

An optical performance monitor having a tunable fiber grating sandwiched between the first and second reflective surfaces of a fiber etalon provides high sensitivity, while simultaneously monitoring an optical data signal. Individual channels within the optical data signal are monitored by tuning the fiber grating over the wavelength range of the optical data signal to measure an intensity of each channel. As the tunable grating scans the wavelength range of interest, it simultaneously changes the resonant cavity length of the etalon, thus allowing the etalon to effectively monitor the tunable grating with a wavelength outside the wavelength range of the optical data signal.

Optical performance monitor

A 1&frac12;&times;2 optical switch has two GRIN lenses, each lens having two ports on its respective outward end face. The switch has a transmissive wedge-shaped switching element disposed between the GRIN lenses. When the switching element is disposed in the path between the GRIN lenses, a single connection is established between a port of the first GRIN lens and a port of the second GRIN lens, while light is prevented from coupling between the remaining ports.

1&frac12;&times;2 optical switch with a transmissive switching element

An optical switch is disclosed having 4-ports. The switch consists of a first GRIN lens having 2 ports adjacent its outwardly facing end face. A second GRIN lens is disposed to receive light from the first GRIN lens and has two ports adjacent its outer end face. In a first state, a first port from the first GRIN lens couples light with a first output port of the second GRIN lens. In a second state, a movable optical element in the form of a light transmissive wedge having a reflective surface, is disposed in the path between first and second GRIN lens, providing a connection between a port of the first GRIN lens and a second port of the second GRIN lens. In a third connect state, the reflective surface of the wedge connects a port of the first GRIN lens and an output port in the same first GRIN lens. Hence an N&times;M optical switch is disclosed.

N x M optical switch

A method and circuit is disclosed wherein two waveguides coupled to an optical resonator are further coupled such that beams propagating therein interfere with one another to provide a desired output response. In one embodiment, multiplexed channels of light can be demultiplexed by the device described heretofore, or alternatively, the phase relationship between these two beams can be altered prior to their being combined to provide, for example, a linearized output response useful in applications such as wavelength locking.

Interferometric optical device including an optical resonator

A method and circuit is disclosed wherein two waveguides coupled to an optical resonant ring resonator are further coupled such that beams propagating therein interfere with one another to provide a desired output response. In one embodiment, multiplexed channels of light can be demultiplexed by the device described heretofore, or alternatively, the phase relationship between these two beams can be altered prior to their being combined to provide, for example, a linearized output response useful in applications such as wavelength locking. By varying the reflectivity of the FSR and the coupling ratios and/or by varying the phase relationship between the two beams, a variety of desired output responses can be realized. By providing suitable coupling ratios and providing optical path lengths of the two waveguides which are identical between the ring resonator and the couplers coupling the two waveguides as well as having the couplers placed 180 degrees opposite to each other, an interleaver/de-interleaver function is realized.

An add-drop optical circuit is provided comprising: a first multiplex/demultiplexer for demultiplexing a composite optical signal having a plurality of channels, a second multiplex/demultiplexer for multiplexing a plurality of signals into a composite optical signal; waveguides disposed between the first demultiplexer and the second multiplexer/demultiplexer; and a plurality of 11/2.times.2 optical switches coupled to at least some of the waveguides for adding and dropping optical signals, the optical switches substantially preventing optical signals from propagating from an add port to drop port.

Growing community of inventors

Fremont, CA, United States of America

Nigel Copner