Seongwoo Suh

US Patent:

7039259, May 2, 2006

Filed:

Jan 16, 2004

Appl. No.:

10/760107

Inventors:

Yossi Corem - Beit Shemesh, IL
Seongwoo Suh - Florham Park NJ, US
Gil Cohen - Livingston NJ, US

Assignee:

Xtellus, Inc. - Florham Park NJ

International Classification:

G02F 1/035

US Classification:

385 3, 385 39, 359279

Abstract:

A fiber optical device, whose wavelength profile can be dynamically controlled in real time by the application of control voltages. The device can be used as a fiber optical gain equalizer or a wavelength selective filtering device which is compact, polarization insensitive, and of low manufacturing costs. The device comprises a stepped transparent substrate, through which the input beam is passed. Within the optical paths of the stepped regions of the substrate, electronically variable phase shifting elements are located, each operative to change the phase of the light passing through its associated step, and thus effectively adding tunability to the height of each step. Planar liquid crystal elements may be used as these elements. The elements may be pixelated, each pixel preferably affecting the phase of the light passing through a fraction of the area of the associated step, such that the interference so can be used to vary the transmission through that step. The pixels thus effectively add tunability to the area of each step.

US Patent:

7435939, Oct 14, 2008

Filed:

May 9, 2004

Appl. No.:

10/556308

Inventors:

SeongWoo Suh - Mount Olive NJ, US
Yossi Corem - Beit Shemesh, IL

Assignee:

XTELLUS Inc. - Morris Plains NJ

International Classification:

G02F 1/01

US Classification:

250216, 359279, 359256

Abstract:

A birefringent, electrically-controlled, wavelength selective, pixelated optical phase shifting device, in which the correct drive voltage for a desired phase shift through any pixel can be determined independently of changes in the drive voltage arising from changes in the environmental conditions, generally temperature. This is achieved by mounting a monitor phase shifting element controlled by its own drive voltage, in close proximity to the pixelated phase shifter, such that the monitor element and the phase shifter experience the same environmental condition. A probe optical beam of predefined wavelength is directed through the monitor element, and the transmitted beam measured as a function of the monitor drive voltage. This functional relationship is used to define the environmental condition in which the monitor element and the phase shifter, are situated, and the correct drive voltage for application to any phase shifter pixel can be determined.

US Patent:

7454100, Nov 18, 2008

Filed:

May 18, 2006

Appl. No.:

11/914946

Inventors:

Yossi Corem - Beit Shemesh, IL
SeongWoo Suh - Mount Olive NJ, US
Boris Frenkel - Jerusalem, IL
Haggai Arbell - Jerusalem, IL

Assignee:

Xtellus, Inc. - Morris Plains NJ

International Classification:

G02B 6/42

US Classification:

385 18, 385 15, 385 16, 385 17

Abstract:

A fiber-optical, wavelength selective switch, especially for channel blocking applications. The input signal is converted to light beams having predefined polarizations relative to the plane in which optical manipulation of the beam is performed. The beams are then preferably laterally expanded in this system plane only, and then spatially dispersed in the beam expansion plane, preferably by means of a diffraction grating. The light is directed through a polarization rotation device, preferably a liquid crystal cell, pixelated along the wavelength dispersive direction such that each pixel operates on a separate wavelength. When the appropriate control voltage is applied to a pixel, the polarization of the light signal passing through that pixel is rotated. The wavelength dispersed beams from all of the pixels are then recombined, and are passed towards a polarization selective device, aligned such that only selected polarization components are transmitted out of the switch.

US Patent:

7558447, Jul 7, 2009

Filed:

Nov 26, 2003

Appl. No.:

10/580832

Inventors:

SeongWoo Suh - Mount Olive NJ, US
Yossi Corem - Beit Shemesh, IL

Assignee:

Xtellus Inc. - Morris Plains NJ

International Classification:

G02B 6/26

US Classification:

385 16, 385 15, 385 18

Abstract:

A single-pole, wavelength selective switch in which the input optical signal is converted to a light beam having a defined polarization, such as S-polarization, with respect to the system plane. The beam is laterally expanded in the system plane, and then spatially dispersed in the same plane as that of the beam expansion, preferably by means of a diffraction grating. The light is directed through a polarization conversion device, preferably a liquid crystal cell, pixelated along the wavelength dispersive direction such that each pixel operates on a separate wavelength. When the appropriate control voltage is applied to a pixel, the polarization of the light signal passing through that pixel is rotated, such as from S to P. The wavelength dispersed beams from the pixels are recombined, and are passed towards another polarizer at the switch output, aligned such that only the selected polarization components are allowed to exit.

US Patent:

7733556, Jun 8, 2010

Filed:

May 9, 2004

Appl. No.:

10/556307

Inventors:

SeongWoo Suh - Mount Olive NJ, US
Yossi Corem - Beit Shemesh, IL

Assignee:

Oclaro (New Jersey), Inc. - Denville NJ

International Classification:

G02F 1/01

US Classification:

359279, 359245, 359238

Abstract:

An optical beam processing device with two serially disposed birefringent elements, each element having its own direction of orientation. At least one element is pixelated with electrodes activated by control signals. The directions of orientation of the elements are aligned such that the phase shift imparted to the beam by an unactivated pixel of one element, cancels the phase shift imparted to the beam by the other element, such that the beam traversing that pixel undergoes zero phase shift. An appropriate control signal adds a phase shift to the beam passing through that pixel, so as to generate an overall phase shift through the device for any desired wavelength, which could not be readily achieved by either of the elements alone. The resulting device is thus able to provide switchable phase shifts of exactly zero and pi, for different wavelengths, generally unattainable by a single element device.

US Patent:

7822303, Oct 26, 2010

Filed:

Sep 10, 2006

Appl. No.:

12/066249

Inventors:

Gil Cohen - Livingston NJ, US
SeongWoo Suh - Budd Lake NJ, US
Yossi Corem - Beit Shemesh, IL

Assignee:

Oclaro (New Jersey), Inc. - Morris Plains NJ

International Classification:

G02B 6/26

US Classification:

385 18, 385 11, 385 16, 385 24, 385 37

Abstract:

A fiber-optical, wavelength selective switch, especially for channel routing with equalization and blocking applications. The input signals are converted to light beams having predefined polarizations (). The beams are then laterally expanded (), and then undergo spatial dispersion in the beam expansion plane. The different wavelength components are directed through a polarization rotation device, pixilated along the wavelength dispersion direction such that each pixel operates on a separate wavelength. Each beam is passed into a pixilated beam steering array (), for directing each wavelength to a desired output port. The beam steering devices can be MEMS-based or Liquid crystal-based, or an LCOS array. When the appropriate voltage is applied to a pixel and its associated beam steering element, the polarization of the light passing through the pixel is rotated and the beam steered to couple to the selected output port.

US Patent:

20030194165, Oct 16, 2003

Filed:

Apr 12, 2002

Appl. No.:

10/120562

Inventors:

Yaron Silberberg - Lehavim, IL
Seongwoo Suh - Florham Park NJ, US
Gil Cohen - Livingston NJ, US

International Classification:

G02B006/27
G02B006/26
G02B006/32

US Classification:

385/011000, 385/027000, 385/039000, 385/033000

Abstract:

A tunable optical filter is provided that includes an array of independently tunable filter elements. Each of the elements is located along a different optical path that extends between an input and an output port. Optical assemblies for receiving an incident optical signal for providing a filtered optical signal are also provided. In one embodiment, polarization independent spectral filtering can be achieved. Wavelength selectable add/drop multiplexers and demultiplexers, dynamic gain equalizers and attenuators, optical channel blockers and branch filters, switches, and modulators are also provided. Furthermore, methods for constructing and operating filters consistent with this invention are also provided.

US Patent:

20040126120, Jul 1, 2004

Filed:

Sep 5, 2003

Appl. No.:

10/657742

Inventors:

Gil Cohen - Livingston NJ, US
Seongwoo Suh - Florham Park NJ, US
Yossi Corem - Beit Shemesh, IL

Assignee:

Xtellus, Inc. - Morris Plains NJ

International Classification:

H04B010/00

US Classification:

398/158000

Abstract:

A gain equalizer in which a multichannel input light signal is split into its separate wavelength components by means of a dispersive element such as a grating, and the spatially separated wavelength components are passed through a linear array of variable optical attenuators based on liquid crystal phase elements which modulate the phase of part of the cross section of the light. The separate attenuated wavelength components are then recombined and output. The attenuation level of each variable optical attenuator is adjusted according to the output of the light as a function of its wavelength components, and in this way, the overall wavelength profile of the output light signal can be adjusted to any predefined form, whether a flattened spectral profile, as in gain equalization applications, or a spectral compensating profile.