David Morris Caplan

US Patent:

6694104, Feb 17, 2004

Filed:

Mar 3, 1999

Appl. No.:

09/261628

Inventors:

David O. Caplan - Concord MA
Mark L. Stevens - Pepperell MA
Don M. Boroson - Needham MA

Assignee:

Massachusetts Institute of Technology - Cambridge MA

International Classification:

H04B 1004

US Classification:

398197, 398140, 375300

Abstract:

A variable-bit-rate communication system is described. The communication system includes a variable-bit-rate transmitter that generates digital data at a first or a second bit rate and a variable-bit-rate receiver that receives the digital data. The digital data comprises a sequence of signaling waveforms having a first or a second duty cycle, respectively, wherein each signaling waveform has the same shape.

US Patent:

6831779, Dec 14, 2004

Filed:

Apr 27, 2001

Appl. No.:

09/845053

Inventors:

David O. Caplan - Bedford MA

Assignee:

Massachusetts Institute of Technology - Cambridge MA

International Classification:

H01S 300

US Classification:

359347, 359333

Abstract:

A high-gain, saturated output, double-pass, fault-tolerant optical amplifier has an extended range of stability, output power, and efficiency and fall back modes of operation. The optical amplifier is typically configured in a two-stage polarization maintaining configuration, employing erbium-doped fibers as the gain media in both of the stages. At least one optical element in a loss-insensitive region of the amplifier can have a loss substantially higher than optical elements in the gain paths outside of the loss-insensitive region without substantially reducing the overall output power and efficiency of the amplifier. These elements can influence the amplified signal waveform, spectrum, signal-to-noise ratio, or subsequent performance in an optical network, as well as amplifier characteristics, such as output power, stability, efficiency, and reliability. The optical amplifier is suitable for both free-space and fiber optic network applications.

US Patent:

7181097, Feb 20, 2007

Filed:

Mar 13, 2002

Appl. No.:

10/097187

Inventors:

David O. Caplan - Billerica MA, US
Walid A. Atia - Lexington MA, US

Assignee:

Massachusetts Institute of Technology - Cambridge MA

International Classification:

G02B 6/12

US Classification:

385 14, 385 24

Abstract:

A system includes an optical transmitter that outputs an optical signal having a substantially Gaussian waveform and an optical receiver that is optically coupled to the optical transmitter and has an impulse response essentially matching the waveform. The impulse response and waveform preferably match in the time domain. The transmitter and receiver may be average-power-limited, using, for example, an erbium-doped fiber amplifier. To achieve a high signal-to-noise ratio, the waveform may be designed to minimize jitter, sample duration, matching parasitics, and inter-symbol interference (ISI). Such a waveform may be a return-to-zero (RZ) Gaussian or Gaussian-like waveform and may be transmitted in a variety of modulation formats. Further, the system may be used in WDM or TDM systems. A method for characterizing the time domain impulse response of an optical element used in the optical receiver is provided, where the method is optionally optimized using deconvolution and/or cross-correlation techniques.

US Patent:

7401355, Jul 15, 2008

Filed:

Apr 30, 2004

Appl. No.:

10/835794

Inventors:

Robert M. Supnik - Carlisle MA, US
David S. Caplan - Acton MA, US
Paul G. Phillips - Westboro MA, US
Michael Banatt - Cambridge MA, US

Assignee:

Sun Microsystems - Santa Clara CA

International Classification:

H04L 29/00

US Classification:

726 11

Abstract:

Methods and systems for load balancing a plurality of entities, such as firewalls, in a network environment are disclosed. In particular, the load balancing of firewalls on a bidirectional traffic path is performed using a single device that controls both incoming and outgoing traffic through the firewalls. The single device may include virtual routers for controlling the bidirectional traffic through the firewalls. A first virtual router may control incoming traffic to the firewalls and the other virtual router may control outgoing traffic to the firewalls. The virtual routers are logical partitions of the device layered on the physical resources of the device. The virtual routers share all or portions of the physical resources of the single device.

US Patent:

20050084270, Apr 21, 2005

Filed:

Jan 29, 2004

Appl. No.:

10/766979

Inventors:

David Caplan - Concord MA, US
Mark Stevens - Pepperell MA, US
Don Boroson - Needham MA, US

International Classification:

H04B010/12

US Classification:

398141000

Abstract:

A variable-bit-rate communication system is described. The communication system includes a variable-bit-rate transmitter that generates digital data at a first or a second bit rate and a variable-bit-rate receiver that receives the digital data. The digital data comprises a sequence of signaling waveforms having a first or a second duty cycle, respectively, wherein each signaling waveform has the same shape.

US Patent:

20080019705, Jan 24, 2008

Filed:

Jan 3, 2007

Appl. No.:

11/649337

Inventors:

David Caplan - Billerica MA, US
Walid Atia - Lexington MA, US

International Classification:

H04B 10/06
G01C 3/08

US Classification:

398202000, 356005050

Abstract:

A system includes an optical transmitter that outputs an optical signal having a substantially Gaussian waveform and an optical receiver that is optically coupled to the optical transmitter and has an impulse response essentially matching the waveform. The impulse response and waveform preferably match in the time domain. The transmitter and receiver may be average-power-limited, using, for example, an erbium-doped fiber amplifier. To achieve a high signal-to-noise ratio, the waveform may be designed to minimize jitter, sample duration, matching parasitics, and inter-symbol interference (ISI). Such a waveform may be a return-to-zero (RZ) Gaussian or Gaussian-like waveform and may be transmitted in a variety of modulation formats. Further, the system may be used in WDM or TDM systems. A method for characterizing the time domain impulse response of an optical element used in the optical receiver is provided, where the method is optionally optimized using deconvolution and/or cross-correlation techniques.

US Patent:

40997154, Jul 11, 1978

Filed:

Apr 22, 1975

Appl. No.:

5/570397

Inventors:

David M. Caplan - Los Alamitos CA

Assignee:

AMF Incorporated - White Plains NY

International Classification:

A63B 3710
A63B 4304

US Classification:

273 63E

Abstract:

Top weight and/or total weight are adjusted by drilling a hole into the ball along a diameter passing through the center of the top weight area and the center of gravity of total ball weight. Weighted plugs are then located at the two centers by an intervening spacer, and the hole closed by a closure cap.

US Patent:

43007597, Nov 17, 1981

Filed:

Mar 31, 1980

Appl. No.:

6/136149

Inventors:

David M. Caplan - Los Alamitos CA

Assignee:

AMF Incorporated - White Plains NY

International Classification:

A63B 3100

US Classification:

272116

Abstract:

Multi-chambered air inflatable aquatic exercise jackets for the arms and legs constructed from plastic sheet material.