Rafael R Gattass

US Patent:

7568365, Aug 4, 2009

Filed:

May 1, 2002

Appl. No.:

10/136160

Inventors:

Chris Schaffer - La Jolla CA, US
André Brodeur - Montreal, CA
Rafael R. Gattass - Jamaica Plain MA, US
Jonathan B. Ashcom - Somerville MA, US
Eric Mazur - Concord MA, US

Assignee:

President & Fellows of Harvard College - Cambridge MA

International Classification:

C03B 32/00

US Classification:

65377, 65386, 65392, 430290, 430321, 2504921

Abstract:

Thermal 3-D microstructuring of photonic structures is provided by depositing laser energy by non-linear absorption into a focal volume about each point of a substrate to be micromachined at a rate greater than the rate that it diffuses thereout to produce a point source of heat in a region of the bulk larger than the focal volume about each point that structurally alters the region of the bulk larger than the focal volume about each point, and by dragging the point source of heat thereby provided point-to-point along any linear and non-linear path to fabricate photonic structures in the bulk of the substrate. Exemplary optical waveguides and optical beamsplitters are thermally micromachined in 3-D in the bulk of a glass substrate. The total number of pulses incident to each point is controlled, either by varying the rate that the point source of heat is scanned point-to-point and/or by varying the repetition rate of the laser, to select the mode supported by the waveguide or beamsplitter to be micromachined. A wide range of passive and active optical and other devices may be thermally micromachined.

US Patent:

7620281, Nov 17, 2009

Filed:

Jul 8, 2008

Appl. No.:

12/169173

Inventors:

Eric Mazur - Concord MA, US
Limin Tong - Hangzhous, CN
Rafael Gattass - Silver Spring MD, US

Assignee:

President & Fellows of Harvard College - Cambridge MA

International Classification:

G02B 6/02
G02B 6/26

US Classification:

385123, 385 48

Abstract:

The present invention provides nanometer-sized diameter silica fibers that exhibit high diameter uniformity and surface smoothness. The silica fibers can have diameters in a range of a about 20 nm to about 1000 nm. An exemplary method according to one embodiment of the invention for generating such fibers utilizes a two-step process in which in an initial step a micrometer sized diameter silica preform fiber is generated, and in a second step, the silica preform is drawn while coupled to a support element to form a nanometer sized diameter silica fiber. The portion of the support element to which the preform is coupled is maintained at a temperature suitable for drawing the nansized fiber, and is preferably controlled to exhibit a temporally stable temperature profile.

US Patent:

20050207713, Sep 22, 2005

Filed:

Dec 15, 2004

Appl. No.:

11/013198

Inventors:

Eric Mazur - Concord MA, US
Limin Tong - Hangzhous, CN
Rafael Gattass - Somerville MA, US

International Classification:

G02B006/02

US Classification:

385123000, 065477000

Abstract:

The present invention provides nanometer-sized diameter silica fibers that exhibit high diameter uniformity and surface smoothness. The silica fibers can have diameters in a range of a about 20 nm to about 1000 nm. An exemplary method according to one embodiment of the invention for generating such fibers utilizes a two-step process in which in an initial step a micrometer sized diameter silica preform fiber is generated, and in a second step, the silica preform is drawn while coupled to a support element to form a nanometer sized diameter silica fiber. The portion of the support element to which the preform is coupled is maintained at a temperature suitable for drawing the nansized fiber, and is preferably controlled to exhibit a temporally stable temperature profile.

US Patent:

20090320529, Dec 31, 2009

Filed:

Aug 3, 2009

Appl. No.:

12/534202

Inventors:

Chris Schaffer - La Jolla CA, US
Andre Brodeur - Montreal, CA
Rafael R. Gattass - Jamaica Plain MA, US
Jonathan B. Ashcom - Somerville MA, US
Eric Mazur - Concord MA, US

Assignee:

PRESIDENT & FELLOWS OF HARVARD COLL - Cambridge MA

International Classification:

C03B 37/09

US Classification:

65509

Abstract:

Thermal 3-D microstructuring of photonic structures is provided by depositing laser energy by non-linear absorption into a focal volume about each point of a substrate to be micromachined at a rate greater than the rate that it diffuses thereout to produce a point source of heat in a region of the bulk larger than the focal volume about each point that structurally alters the region of the bulk larger than the focal volume about each point, and by dragging the point source of heat thereby provided point-to-point along any linear and non-linear path to fabricate photonic structures in the bulk of the substrate. Exemplary optical waveguides and optical beamsplitters are thermally micromachined in 3-D in the bulk of a glass substrate. The total number of pulses incident to each point is controlled, either by varying the rate that the point source of heat is scanned point-to-point and/or by varying the repetition rate of the laser, to select the mode supported by the waveguide or beamsplitter to be micromachined. A wide range of passive and active optical and other devices may be thermally micromachined.

US Patent:

20120039560, Feb 16, 2012

Filed:

Jan 8, 2010

Appl. No.:

13/143451

Inventors:

Eric Mazur - Concord MA, US
Rafael R. Gattass - Silver Spring MD, US
Geoffry T. Svacha - Somerville MA, US
Katherine C.f. Phillips - Cambridge MA, US
Christopher C. Evans - Cambridge MA, US

Assignee:

President & Fellows of Harvard College - Cambridge MA

International Classification:

G02F 1/035
G02B 6/12

US Classification:

385 2, 385 3, 385 14

Abstract:

The present invention provides optical devices that employ nonlinear optical effects for processing optical signals. For example, such an optical device can include a nano-sized interferometric component that provides an optical output signal via interference of two input signals subsequent to their asymmetric nonlinear phase accumulation. The interferometric element can have a variety of configurations, such as Sagnac, Mach-Zehnder or Michelson configurations.

US Patent:

20130188240, Jul 25, 2013

Filed:

Jan 16, 2013

Appl. No.:

13/742563

Inventors:

Leslie Brandon Shaw - Woodbridge VA, US
Rafael R. Gattass - Washington DC, US
Jasbinder S. Sanghera - Ashburn VA, US
Ishwar D. Aggarwal - Charlotte NC, US

International Classification:

G02F 1/35

US Classification:

359326

Abstract:

A method of generating a supercontinuum in chalcogenide fiber with a pump light comprising a short pulse fiber laser or diode laser operating with a wavelength of μm or greater that is wavelength shifted through a nonlinear fiber one or more times and amplified one or more times and launched into a chalcogenide fiber whereby the spectrum is broadened in the chalcogenide fiber through various nonlinear processes to generate a supercontinuum within the mid-IR from to greater than μm.

US Patent:

20130188660, Jul 25, 2013

Filed:

Jan 16, 2013

Appl. No.:

13/742566

Inventors:

Leslie Brandon Shaw - Woodbridge VA, US
Rafael R. Gattass - Washington DC, US
Jasbinder S. Sanghera - Ashburn VA, US
Ishwar D. Aggarwal - Charlotte NC, US

International Classification:

H01S 3/00

US Classification:

372 25

Abstract:

A method of generating ultrashort pulses with wavelengths greater than 2 μm comprising a short pulse diode laser or fiber laser operating at a wavelength of 1 μm or greater with a pulse width of 10 ps or greater, one or more amplification stages to increase the peak power of the pulsed source, a nonlinear fiber stage whereby the dispersion of the nonlinear fiber is anomalous at the pulsed source wavelength such that the fiber breaks up the pulse into a series of sub-ps pulse train through modulation instability which may be seeded by spontaneous noise which are then wavelength shifted in one or more stages by soliton self frequency shift in anomalous dispersion fiber or Raman in normal dispersion fiber and amplified in one or more stages to generate a high peak power ultrashort pulse (

US Patent:

20140014858, Jan 16, 2014

Filed:

Jul 11, 2013

Appl. No.:

13/939514

Inventors:

Rafael R. Gattass - Washington DC, US
Leslie Brandon Shaw - Woodbridge VA, US
Jasbinder S. Sanghera - Ashburn VA, US
Ishwar D. Aggarwal - Charlotte NC, US
Lynda E. Busse - Alexandria VA, US

International Classification:

G02B 27/10

US Classification:

2504951, 29428

Abstract:

An infrared laser source system that combines laser emitters through an optical waveguide. Each emitter is coupled to a port of the optical waveguide and the waveguided signal is combined to provide a spatially combined laser source with a single common exit aperture. The materials used for waveguiding allow the propagation of wavelengths in the infrared. The system can be used for combining multiple laser emitters to increase the total output power and/or for combination of multiple emitters with different wavelength for increased spectral coverage out of the laser system.