Lucent Technologies Inc.

Alcatel-lucent USA Inc.

Alcatel Lucent

Dan Mark Marom

Christopher Richard Doerr

Dennis Stanley Greywall

David T Neilson

Christophe Jean Dorrer

Roland Ryf

Nagesh R Basavanhally

Clinton R Giles

Randy Clinton Giles

Inuk Kang

Juerg Leuthold

Mihaela Dinu

Christophe J Dorrer

A communication system adapted to use wavelength (frequency) division multiplexing for quantum-key distribution (QKD) and having a transmitter coupled to a receiver via a transmission link. In one embodiment, the receiver is adapted to (i) phase-shift a local oscillator (LO) signal generated at the receiver, (ii) combine the LO signal with a quantum-information (QI) signal received via the transmission link from the transmitter to produce interference signals, (iii) measure an intensity difference for these interference signals, and (iv) phase-lock the LO signal to the QI signal based on the measurement result. In one configuration, the QI signal has a plurality of pilot frequency components, each carrying a training signal, and a plurality of QKD frequency components, each carrying quantum key data. Advantageously, the system can maintain a phase lock for the QKD frequency components of the QI and LO signals, while the QKD frequency components of the QI signal continuously carry quantum key data.

Phase locking in a multi-channel quantum communication system

The invention includes a method and apparatus for controlling curvatures of light directing devices. The apparatus includes a first substrate portion having formed therein a plurality of cavities, and a substantially flexible membrane disposed over the cavities for forming a respective plurality of light directing mechanisms, the light directing mechanisms disposed over the cavities. The respective curvatures of the light directing mechanisms are set using a pressure difference across each of the membrane portions disposed over the cavities. The respective curvatures of the light directing mechanisms may be controllably adjusted during operation of the light directing mechanisms.

Method and apparatus for controlling curvatures of microlenses and micromirrors

A signal identification method for efficiently identifying Dense Wavelength Division Multiplexing (DWDM) channel modulation formats, signal powers, and center frequency detuning of signals that may be used in conjunction with telecom-grade monitoring equipment. The method utilizes least-square curve fitting estimates applied to a set of curves, each curve is characteristic of a modulation format and rate. For each least-square estimate an error value is calculated, and a curve fit with the least error is selected as the identified signal format for a signal.

Signal identification method

An optical system having a spatial light modulator (SLM), in which each pixel has an optical cavity and is adapted to: (i) change the intensity of a reflected beam by changing the size of the cavity and (ii) change the phase of the reflected beam by changing the position of the cavity with respect to a reference plane. In one embodiment, the optical system has optics configured to image the apertures of an optical input mask onto the pixels of the SLM and to form an optical spot array by imaging the light reflected by the pixels onto a plane orthogonal to the plane of the mask. Each aperture can be configured to have a transmission pattern to spatially modulate the light imaged onto the corresponding pixel, thereby enabling control of the spatial mode at the corresponding spot in the optical spot array.

Spot array generation using a MEMS light modulator

A free-space optical switch for switching light beams between waveguides of planar lightwave circuits (PLCs). Switching is accomplished using a combination of lenses and micromirrors. The lenses and the controlled tilt of the micromirrors can establish a one-to-one interconnection path between waveguides of the PLCs.

Apparatus for free-space switching between planar lightwave circuits

A MEMS device that enables an optical subsystem (e.g., an optical switch) having an optical component optically coupled to the MEMS device via free space to achieve optical alignment between the optical component and the MEMS device without moving the optical component with respect to the stationary part of the MEMS device. In one embodiment, a MEMS device of the invention has a stationary part and a movable part movably connected to the stationary part. The movable part has a platform and a plurality of mirrors mounted on the platform, wherein (i) each mirror is adapted to move with respect to the platform independent of other mirrors and (ii) the platform is adapted to move with respect to the stationary part together with the mirrors.

MEMS-based alignment of optical components

An apparatus and method are provided for manipulating light beams propagated through an optical apparatus that includes a planar lightwave circuit (PLC) and free-space optics unit. A multi-wave optical signal coupled to the PLC is propagated through a first and second waveguide array to generate a phased array output at an edge facet of the PLC. The phased array output at the edge facet is spatially Fourier transformed by the lens to generate a spectrally resolved image having a discrete light spot for each channel of the input optical signal, which is coupled to a pixelated optical receiving unit. When the optical receiving unit is a reflector, one or more of the discrete light spot are reflected to a desired waveguide array of a PLC to produce a desired output. When the optical receiving unit is a pixelated transmissive modulator, one or more of the discrete light spot are modulated as they pass through the modulator.

Method and apparatus for wavelength-selective switches and modulators

The invention includes an apparatus for modulating an optical signal. The apparatus includes a spatial dispersion mechanism and a modulating mechanism. The spatial dispersion mechanism spatially disperses the optical signal. The spatially dispersed optical signal has a plurality of frequency components where each frequency component has an associated beam size. The modulating mechanism includes an array of modulating components where each modulating component has a pitch. The pitch of each modulating component is substantially equal to or less than the beam size of each frequency component.

Apparatus for reducing drops in a transmission spectrum due to inter-pixel gaps

An apparatus and method are provided for manipulating light beams propagated through PLCs in free space. Light beams propagated in through an input/output waveguide of a PLC are propagated through a waveguide array to generate a phased array output at an edge facet of the PLC. The phased array output at the edge facet is spatially Fourier transformed by a lens in free space, generating a spectrally resolved image at the back focal plane of the lens. The spectrally resolved image is reflected, at least in part, by a reflector device and coupled into a desired waveguide array of a PLC to produce a desired output.

Method and apparatus for free-space optical switching

The invention includes a method and apparatus for modulating one or both of spectral phase and amplitude of a received optical signal. The apparatus includes a spatial dispersion mechanism for spatially dispersing the received optical signal to enable optical communication of the received optical signal to an array of modulators. The apparatus includes a modulating mechanism having a first modulating component and a second modulating component. A first portion of the spatially dispersed optical signal is incident on the first modulating component and a second portion of the spatially dispersed optical signal is incident on the second modulating portion. The apparatus further includes a controller coupled to the modulating mechanism. The controller is adapted for moving the first and second modulating components in a direction normal to their planes for modulating one or both of phase and amplitude of the received optical signal.

Apparatus for modulating one or both of spectral phase and amplitude of an optical signal

An optical pulse shaper without polarization dependencies includes, a planar lightwave circuit (PLC) having an arrayed waveguide and free space optics, combined with a lens and micromirror array characterized by piston-motion. The micromirror array is coupled to a controller that provides signals to the array for adjusting the positions of the micromirrors, which are used as a spatial light modulator to provide at least phase modulation to one or more of the separated frequency components of an input optical signal. The frequency separated components, including modified components, are recombined and directed back to the PLC to form a synthesized optical pulse. Information regarding the characteristics of the synthesized optical pulse is extracted from a spectrogram of that pulse. Extracted information is provided to the controller and responsive thereto the controller may generate signals for adjusting the position of one or more micromirrors.

Optical pulse shaper having hybrid planar lightwave circuit and free-space optics with MEMS piston-motion micromirrors and feedback control

A fully integrated microelectromechanical (MEMS) lxK wavelength selective switch (WSS) includes an array of N solid-immersion micromirrors (SIMs) and a K+1 dispersion waveguide arrays that are integrally fabricated together. In one embodiment, the WSS is fabricated in Silicon. In another embodiment, the N actuators of the SIMs are etched in the Silicon layer of a Silicon-on Insulator (SOI) wafer. Thereafter, a Silica layer is deposited on the Silicon layer and the K+1 waveguide arrays and the mirrors for the N SIMs are etched in that Silica layer. In yet another embodiment, the K+1 dispersion waveguide arrays, except for a small portion of the common confocal coupler, are fabricated using a material selected from a group including Silica, sol-gel, polymers, that is deposited on a first wafer selected from a group including Silicon, Saphire, or other glass insulator material and the remaining portion of the common confocal coupler and the N SIMs are fabricated in a Silicon wafer, and the first wafer and Silicon wafer are then butt-coupled together.

Integrated microelectromechanical wavelength selective switch and method of making same

The invention includes an apparatus for modulating an optical signal. The apparatus includes a modulating mechanism comprising a plurality of modulating component arrays, each modulating component array comprising a plurality of modulating components, wherein adjacent ones of the plurality of modulating components in each modulating component array are separated by gaps, and wherein adjacent ones of the plurality of modulating component arrays are offset along a dispersion direction of an incident optical signal such that the gaps associated with the adjacent ones of the plurality of modulating component arrays are offset. In one embodiment, rows of the modulating components in the modulating component arrays are offset along the dispersion direction of the incident optical signal by a fraction of the modulating component pitch.

Wavelength-selective switches (WSSs) having embedded multiplexer or demultiplexer functionality include a stack of planar waveguide circuits (PLCs) in which all but one of the PLCs have identical features consisting of a single waveguide connected to a free space region, further connected to a waveguide array that terminates at the PLC edge facet, which are placed at the front focal plane of a lens, generating a spectrally resolved optical signal at the back focal plane of the lens. Due to the use of a single lens, the spectrally resolved optical signal of all the PLCs are superimposed, differing only by propagation direction. A tilting micro-mirror array at the back focal plane reflects the spectral components, implementing a wavelength-selective switch. The reflected light can couple to any of the remaining PLCs, for multiplexing, or to the different PLC in the stack, which implements the multiplexer/demultiplexer.

Wavelength-selective switch and integrated wavelength demultiplexer using stacked planar lightwave circuits

The invention includes an apparatus for receiving an optical signal from an optical input means and directing the optical signal to one of a plurality of optical output means. The apparatus includes a solid signal propagating material having a refractive index greater than the refractive index of air. The solid signal propagating material includes a first transparent surface optically cooperating with the optical input and output means, a second transparent surface optically cooperating with a first light directing mechanism, and a reflective surface optically cooperating with the first light directing mechanism. A first reflecting component of the light directing mechanism directs a received optical signal to a second reflecting component of the light directing mechanism via the reflective surface of the signal propagating material. The second reflecting component of the light directing mechanism directs the respective incident optical signal to the selected one of the plurality of optical output means.

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Howell, NJ, United States of America

Dan Mark Marom