Eric G Swanson

US Patent:

6396051, May 28, 2002

Filed:

Jun 7, 2000

Appl. No.:

09/589942

Inventors:

Jinghui Li - North Billerica MA
Eric Swanson - Acton MA
John Zyskind - Concord MA

Assignee:

Sycamore Networks, Inc. - Chelmsford MA

International Classification:

G01J 400

US Classification:

25022718, 359110

Abstract:

An apparatus for measuring the optical-signal-to-noise ratio (OSNR) of an optical system is adapted to function in single channel or in multi-channel wavelength division multiplexed optical communication systems. An optical signal spectrum and a center frequency characterize the optical signals. A narrow-band notch filter, realized by an in-fiber Bragg grating, is utilized to remove a component of the signal so the remaining signal can be measured. When multiple channels are present, a bandpass filter is used to select the part of the multiplexed signal to be measured. Both the narrow-band notch filter and the bandpass filter can be tunable to further extend the capabilities of the system. Two detectors are utilized with the power in the channel being measured by a low-gain detector and the power in the noise being measured by a high-gain detector. A processor receives the detector outputs, calculates OSNR, and controls the tunable components.

US Patent:

6426713, Jul 30, 2002

Filed:

Oct 25, 2000

Appl. No.:

09/695708

Inventors:

Aryesh Amar - Nashua NH
Edwin De Angel - Austin TX
Eric J. Swanson - Buda TX

Assignee:

Cirrus Logic, Inc. - Austin

International Classification:

H03M 106

US Classification:

341118, 341120, 341144

Abstract:

In a signal processing integrated circuit having a plurality of physical channels and a plurality of gain registers, a plurality of offset registers and an plurality of setup registers, mechanisms are provided to assign one of a plurality of gain registers independently of a selected one of a plurality of offset registers when processing signals from a physical channel.

US Patent:

6430201, Aug 6, 2002

Filed:

Dec 21, 1999

Appl. No.:

09/468192

Inventors:

Murat Azizoglu - North Billercia MA
Thomas Kong - Brookline MA
Eric A. Swanson - Acton MA

Assignee:

Sycamore Networks, Inc. - Chelmsford MA

International Classification:

H04J 304

US Classification:

370535

Abstract:

Multiple gigabit Ethernet (GbE) and Fiber Channel (FC) signals are multiplexed and transported on a wavelength-division multiplexed (WDM) communications link using synchronous optical network (SONET) signaling. A transmitter decodes the 8b/10b encoded GbE/FC signals to reduce their respective signaling rates to no greater than the payload data rate of an OC- signal used on the link. The decoded signal are packetized into fixed-size packets in order to append a stream identifier used for de-multiplexing at the receive end. The packetized streams are multiplexed together and formatted into the OC- signal, which is transmitted over the communications link. A receiver de-multiplexes the received signal to obtain the packet streams, converts the packet streams to the corresponding decoded signals, and re-encodes each signal to re-create the original GbE/FC signals. A pair of interfaces can be arranged to provide independent adding or dropping of the GbE/FC signals that share the same wavelength.

US Patent:

6433904, Aug 13, 2002

Filed:

Jul 27, 1999

Appl. No.:

09/361927

Inventors:

Eric A. Swanson - Acton MA
Richard Barry - Brookline MA
Murat Azizoglu - North Billercia MA

Assignee:

Sycamore Networks, Inc. - Chelmsford MA

International Classification:

H04J 1402

US Classification:

359133, 359110, 359124, 359161, 359173, 359181, 359187, 359188, 359194, 359195

Abstract:

Data transmission apparatus includes first and second optical transmitters coupled to an optical link. A forward error correction (FEC) coder is coupled to the input of the second optical transmitter. A first information signal having a first information rate is provided to the first optical transmitter, and a second information signal having a second information rate is provided to the second optical transmitter. The use of the FEC coder enables the second information signal to have a higher information rate than the first information signal, while simultaneously enabling the respective output power levels of the first and second optical amplifiers to be substantially equal. The data transmission apparatus achieves higher data transmission capacity while retaining compatibility with pre-existing fiber spans and amplifier nodes. An optical transmission system incorporates an optical transmitter and an optical receiver having certain transmission characteristics, such as output power level, decision threshold level, etc. , that are adjustable in response to bit error rate information.

US Patent:

6445939, Sep 3, 2002

Filed:

Aug 9, 1999

Appl. No.:

09/370756

Inventors:

Eric Swanson - Acton MA
Christopher L. Petersen - Carlise MA
Edward McNamara - Chelmsford MA
Ronald B. Lamport - Pelham NH
David L. Kelly - Westford MA

Assignee:

LightLab Imaging, LLC - Westford MA

International Classification:

A61B 500

US Classification:

600342, 600434, 385 33, 385 34

Abstract:

Ultra-small optical probes comprising a single-mode optical fiber and a lens which has substantially the same diameter as the optical fiber. The optical fiber and lens are positioned in a probe housing which is in the form of an insertional medical device such as a guidewire. Connector elements are provided to facilitate the attachment of the probe to an optical system and the quick disconnection of the probe from the optical system. The probe is used to obtain optical measurements in situ in the body of an organism and can be used to guide interventional procedures by a surgeon.

US Patent:

6456409, Sep 24, 2002

Filed:

Jul 16, 2001

Appl. No.:

09/906195

Inventors:

Jianying Zhou - Acton MA
Richard A. Barry - Brookline MA
Murat Azizoglu - North Billerica MA
Eric A. Swanson - Acton MA

Assignee:

Sycamore Networks, Inc. - Chelmsford MA

International Classification:

H04J 1402

US Classification:

359124, 359161

Abstract:

A Dense Wavelength Division Multiplexed (DWDM) optical transmission system that compensates for unequal channel performance over an extended fiber transmission distance. The DWDM optical transmission system includes optical transmitters at a transmitter end of a transmission path for transmitting respective channels of information at different wavelengths, a first pre-emphasis device for performing a first pre-emphasis technique on the respective channels, an optical multiplexor for combining the respective channels into a multi-wavelength optical signal for transmission on a single transmission fiber, at least one optical amplifier for amplifying the optical signal along the path, at least one second pre-emphasis device disposed along the path for performing a second pre-emphasis technique on the respective channels, an optical de-multiplexor for separating the optical signal into its component channels, and optical receivers at a receiver end of the path for receiving and detecting the information carried by the respective channels. The first and second pre-emphasis techniques performed by the respective first and second pre-emphasis devices compensate for unequal channel performance along the transmission path over a desired fiber transmission distance.

US Patent:

6485413, Nov 26, 2002

Filed:

Mar 6, 1998

Appl. No.:

09/036283

Inventors:

Stephen A. Boppart - Boston MA
Gary J. Tearney - Cambridge MA
Brett E. Bouma - Boston MA
Mark E. Brezinski - Malden MA
James G. Fujimoto - Cambridge MA
Eric A. Swanson - Acton MA

Assignee:

The General Hospital Corporation - Boston MA

International Classification:

A61B 106

US Classification:

600160, 600129, 600477, 600478, 356345, 356349

Abstract:

An imaging system for performing forward scanning imaging for application to therapeutic and diagnostic devises used in medical procedures. The imaging system includes forward directed optical coherence tomography (OCT), and non-retroreflected forward scanning OCT. Also interferometric imaging and ranging techniques and fluorescent, Raman, two-photon, and diffuse wave imaging can be used. The forward scanning mechanisms include a cam attached to a motor, pneumatic devices, a pivoting device, piezoelectric transducers, electrostatic driven slides for substantially transverse scanning; counter-rotating prisms, and offset lenses are used for arbitrary scanning. The imaging system of the invention is applied to hand held probes including probes integrated with surgical probes, scalpels, scissors, forceps and biopsy instruments. Hand held probes include forward scanning lasers. The imaging system is also applicable to laparoscopes and endoscopes for diagnostc and therapeutic intervention in body orifices, canals, tubes, ducts, vessels and cavities of the body.

US Patent:

6496305, Dec 17, 2002

Filed:

Jul 23, 2001

Appl. No.:

09/911926

Inventors:

Derek Spock - Boston MA
Murat Azizoglu - Concord MA
Jonathan C. Bloch - Boston MA
Farzana I. Khatri - Andover MA
Vijayanand Vusirikala - Westford MA
Eric Arthur Swanson - Acton MA

Assignee:

Sycamore Networks, Inc. - Chelmsford MA

International Classification:

H01S 300

US Classification:

359349, 3593412

Abstract:

An optical amplifier for a 4-fiber system having two inputs and outputs is provided that makes use of a single amplifier rather than two separate amplifiers. The optical amplifier node makes use of an interleaver before and after the single amplifier to demultiplex and multiplex even and odd channel signals traveling in opposite directions. The arrangement can also amplify wide channel spaced signals traveling through a plurality of optical fibers. The optical amplifier node can be combined with other like amplifier nodes to provide more complex amplifier solutions at reduced costs due to the need for only half of the typical number of amplifiers. The optical amplifier node can also be combined with, e. g. , variable optical attenuators, L/C/S filters, channel add/drop, co- and counter-propagating Raman amplification, and dispersion compensation modules to modify the optical signals as desired.