Victor V Khitrov

US Patent:

8515220, Aug 20, 2013

Filed:

Apr 12, 2012

Appl. No.:

13/445404

Inventors:

Victor Khitrov - Redondo Beach CA, US
David A. Rockwell - Culver City CA, US

Assignee:

Raytheon Company - Waltham MA

International Classification:

G02B 6/12
G02B 6/26
G02B 6/00
G02B 6/42

US Classification:

385 14, 385 43

Abstract:

An optical fiber coupler configured to couple signal beams into a non-circularly shaped output optical beam or device is provided. The coupler includes an adiabatically tapered optical device. The tapered optical device has a core taper ratio equal to the ratio between a second core diameter and a first core diameter and a mode taper ratio equal to the ratio between a second mode field diameter and a first mode field diameter. The mode taper ratio is greater than the core taper ratio. A spacing between adjacent cores at the output end is less than a spacing between adjacent cores at the input end by approximately the core taper ratio, thereby increasing brightness of a combined output optical signal relative to the combined brightness of the plurality of input optical fibers by approximately a factor equal to the ratio of the mode taper ratio to the core taper ratio.

US Patent:

20090262761, Oct 22, 2009

Filed:

Jan 22, 2009

Appl. No.:

12/358012

Inventors:

Victor Khitrov - South Windsor CT, US

Assignee:

NUFERN - East Granby CT

International Classification:

H01S 3/30

US Classification:

372 6

Abstract:

Optical fiber source for providing polarized optical pulses, comprising a Q-switched fiber laser for providing substantially unpolarized seed pulses of optical energy, where the Q-switched fiber laser can comprise a laser cavity having a Q-switch and an optical fiber comprising a gain medium, where the optical fiber need not be a polarizing or polarization maintaining optical fiber; a passive polarizing element arranged to receive and substantially polarize the substantially unpolarized seed pulses; and a polarization maintaining fiber amplifier arranged for receiving the polarized seed pulses. The polarization maintaining fiber amplifier can comprise a selected polarizing or polarization maintaining fiber having a core comprising a gain medium for amplifying the substantially polarized seed pulses, where the core can be normally multimode at a an operating wavelength of the optical fiber source. The fiber amplifier can provide substantially polarized output pulses. In one practice of the invention, the pulse power instability, over at least 100 consecutive pulses, is no greater than 10%.

US Patent:

20230067875, Mar 2, 2023

Filed:

Aug 31, 2021

Appl. No.:

17/462734

Inventors:

- Livermore CA, US
Sara Elizabeth HARRISON - Fremont CA, US
Catherine E. REINHARDT - Livermore CA, US
Payal Kamlesh SINGH - San Diego CA, US
Victor V. KHITROV - San Ramon CA, US

International Classification:

G02B 6/255
G02B 6/36
C03C 25/68

Abstract:

The present disclosure relates to a method of forming a tapered optical fiber, where the optical fiber has a cladding encasing a core and has an initial outer diameter. The method involves applying opposing forces to spaced apart sections of the optical fiber. The spaced apart sections define a length portion representing a waist region. While applying the opposing forces, simultaneously applying heat to the waist region to gradually produce a taper of the optical fiber within the waist region. The taper has a first diameter at a midpoint of the waist region which is less than the initial outer diameter. An etch operation is then performed by chemically etching at least a subportion of the waist region of the optical fiber to reduce the subportion to a second diameter which is less than the first diameter.

US Patent:

20230011108, Jan 12, 2023

Filed:

Jul 9, 2021

Appl. No.:

17/372366

Inventors:

- Livermore CA, US
Adam Conway - Livermore CA, US
Lars F. Voss - Livermore CA, US
Joseph D. Schneider - Livermore CA, US
Tammy Chang - Livermore CA, US
Caitlin Anne Chapin - Livermore CA, US
John Berns Lancaster - Livermore CA, US
Steve Hawkins - Livermore CA, US
Victor Valeryevich Khitrov - Livermore CA, US

International Classification:

G02B 6/26

Abstract:

Methods and devices for illuminating a photoconductive switch consisting of an optically actuated photoconductive material situated between two electrodes are described. Light from a light source is coupled to an optical fiber, which is attached to a frustum, the other side of which is proximate to the photoconductive switch. Light from the optical fiber enters the frustum, spreads out, and enters the photoconductive switch via the top-side electrode. Some of the light is absorbed, while the remaining light reflects off the bottom-side electrode, travels back through the photoconductive switch, and any unabsorbed light reenters the frustum. The geometry of the frustum is configured such that most of the light reflects back into the switch itself with only a negligible fraction escaping from the optical fiber, which advantageously results in near total utilization of the light.

US Patent:

20210359484, Nov 18, 2021

Filed:

May 11, 2021

Appl. No.:

17/317752

Inventors:

- Livermore CA, US
Jay W. Dawson - Livermore CA, US
Victor V. Khitrov - San Ramon CA, US
Cody W. Mart - Livermore CA, US
Michael J. Messerly - Danville CA, US
Michael Runkel - Livermore CA, US
Charles X. Yu - Pleasanton CA, US

International Classification:

H01S 3/067
H01S 3/30

Abstract:

The present technology provides large mode area optical fibers engineered to have normal dispersion around 1600 nm, enabling high power Raman amplification at eye safer wavelengths. The fibers can have a main core and one or more side cores disposed relative to the main core so that modes of the main core and the one or more side cores hybridize into supermodes with modified dispersion.

US Patent:

20190310420, Oct 10, 2019

Filed:

Jun 18, 2019

Appl. No.:

16/445033

Inventors:

- Livermore CA, US
Diana C. Chen - Fremont CA, US
Matthew J. Cook - Brentwood CA, US
Robert P. Crist - Tracy CA, US
Derrek R. Drachenberg - Livermore CA, US
Jay W. Dawson - Livermore CA, US
Victor V. Khitrov - San Ramon CA, US
Leily Kiani - Livermore CA, US
Michael J. Messerly - Danville CA, US
Paul H. Pax - Livermore CA, US
Nick Schenkel - Livermore CA, US

Assignee:

Lawrence Livermore National Security, LLC - Livermore CA

International Classification:

G02B 6/293

Abstract:

An all fiber wavelength selective coupler provides wavelength selective transfer of optical energy between two or more separated waveguides. The coupler includes signal cores that are separated enough that they can be fusion spliced to standard fibers as lead-in and lead-out pigtails. A bridge between the signal cores facilitates transfer of the optical energy through a process of evanescent coupling. In one example, the bridge is formed of a series of graded index cores.

US Patent:

20170229834, Aug 10, 2017

Filed:

Oct 7, 2016

Appl. No.:

15/288590

Inventors:

- Livermore CA, US
Graham S. Allen - Pleasanton CA, US
Jay W. Dawson - Livermore CA, US
Derrek Reginald Drachenberg - Livermore CA, US
Victor V. Khitrov - San Ramon CA, US
Michael J. Messerly - Danville CA, US
Nick Schenkel - Livermore CA, US

Assignee:

Lawrence Livermore National Security, LLC - Livermore CA

International Classification:

H01S 3/067
G02B 6/14
H01S 3/16
G02B 6/02

Abstract:

Rare earth doped fiber lasers can be robust and efficient sources of high quality light, but are usually limited to the highest gain transitions of the active species. But rare earths typically possess a multitude of potentially useful transitions that might be accessed if the dominant transition can be suppressed. In fiber lasers this suppression is complicated by the very high net gain the dominant transitions exhibit; effective suppression requires some mechanism distributed along the length of the fiber. We have developed a novel waveguide with resonant leakage elements that frustrate guidance at well-defined and selectable wavelengths. Based on this waveguide, we have fabricated a Large Mode Area Neodymium doped fiber with suppression of the four-level transition around 1060 nm, and demonstrated lasing on the three-level transition at 930 nm with good efficiency.

US Patent:

20170229838, Aug 10, 2017

Filed:

Oct 7, 2016

Appl. No.:

15/288810

Inventors:

- Livermore CA, US
Graham S. Allen - Livermore CA, US
Derrek Reginald Drachenberg - Livermore CA, US
Victor V. Khitrov - San Ramon CA, US
Michael J. Messerly - Danville CA, US
Paul H. Pax - Livermore CA, US
Nick Schenkel - Livermore CA, US

Assignee:

Lawrence Livermore National Security, LLC - Livermore CA

International Classification:

H01S 3/16
H01S 3/094
H01S 3/067

Abstract:

An Nd optical fiber laser and amplifier operating in the wavelength range from 1300 to 1450 nm is described. The fiber includes a rare earth doped optical amplifier or laser operating within this wavelength band is based upon an optical fiber that guides light in this wavelength band. The waveguide structure attenuates light in the wavelength range from 850 nm to 950 nm and from 1050 nm to 1150 nm.