Raytheon Company

Ofs Fitel, LLC

Vladimir V Shkunov

David Alan Rockwell

Alexander A Betin

Robert William Byren

Robin A Reeder

David John DiGiovanni

Michael Ushinsky

Scott T Johnson

Dennis J Trevor

Friedrich P Strohkendl

Vijay Murgai

Joshua Nathan Wentlandt

James Randolph Mulroy

David J Digiovanni

Joshua N Wentlandt

An apparatus includes an optical fiber configured to transport an optical signal. A cross-section of the optical fiber has a longer slow-axis dimension and a shorter fast-axis dimension. The optical fiber includes a core configured to receive and amplify the optical signal, end features optically coupled to the core at opposite ends of the core, and a cladding surrounding the core and end features. The core has a height in the slow-axis dimension and a width in the fast-axis dimension. Each end feature has a height in the slow-axis dimension and a width in the fast-axis dimension. The core has a lower bend loss than the end features. The optical fiber is configured to confine optical power of a fundamental mode in the core and allow optical power of higher-order mode(s) to leak from the core into the end features. Each end feature's height is less than the core's width.

Optical fiber for light amplification having a core with low bend loss and end features with high bend loss and related method

Air core optical fiber structures in which the cladding is composed of an engineered optical metamaterial having a refractive index less than unity for at least one specific wavelength band and provides for total internal reflection of optical energy between the air core and metamaterial cladding. According to certain examples, a method of guiding optical energy includes constructing a hollow core optical fiber with an all-dielectric optical metamaterial cladding, coupling optical energy into the optical fiber having an operating wavelength near a resonance of the metamaterial cladding, and guiding the optical energy within the hollow core optical fiber by total internal reflection.

Low-latency, hollow-core optical fiber with total internal reflection mode confinement

An apparatus includes an optical fiber configured to transport an optical signal. The optical fiber includes a core configured to receive and amplify the optical signal. The optical fiber also includes end features optically coupled to opposite ends of the core. The core has a lower bend loss than the end features. The optical fiber further includes a cladding surrounding the core and the end features. The optical fiber is configured to confine optical power of a fundamental mode in the core. The optical fiber is also configured to allow optical power of one or more higher-order modes to leak from the core into the end features.

In various embodiments, an optical fiber includes a core having a relatively large area selected so as to raise a threshold of stimulated Raman scattering or stimulated Brillouin scattering, or both, the core having a high aspect ratio elongated cross-section and having a first refractive index. The core is narrower in a fast-axis direction and wider in a slow-axis direction, such that the fiber is mechanically flexible in the fast-axis direction and is mechanically rigid in the slow-axis direction.

Method and apparatus for fiber delivery of high power laser beams

A method and system for reducing optical signal fading in an optical communication system include: dynamically obtaining turbulence-induced divergence and deviations of pointing direction for the atmosphere where an optical signal to be transmitted through; generating a single-transverse-mode laser beam of a predetermined diameter as the optical signal; dynamically varying the diameter of the laser beam to match the obtained turbulence-induced divergence of the atmosphere with a backtrack pointing direction; and transmitting the laser beam with varying diameter to a remote transceiver, as the optical signal.

Apparatus and method for reducing signal fading due to atmospheric turbulence

According to an embodiment of the disclosure, a Raman generator includes a Raman medium and one or more optical elements. The Raman medium is configured to receive a pump pulse at a first wavelength and shift at least a portion of the pump pulse energy or power into a Stokes-shifted pulse at a second wavelength. The one or more optical elements are configured to pass the pump pulse and the Stokes-shifted pulse multiple times through the Raman medium. Each pass of the pulses through the Raman medium follows a path. Each path is parallel or anti-parallel to the other paths.

Compact Raman generators

High aspect ratio core optical fiber designs, which could be semi-guiding, including a core region having a first refractive index and a high aspect ratio elongated cross-section along a slow axis direction, are described. An internal cladding having a second refractive index sandwiches the core and acts as a fast-axis signal cladding. The core has an edge region at both of its short edges that is in contract with edge-cladding regions having a barbell shape. The refractive index of the core regions, the refractive index of the internal claddings, and the refractive index of the edge-cladding regions, are selected so as to maximize the optical power of a lowest-order mode propagating in the fiber core, and to minimize the optical power of the next-order modes in the fiber core. A process to fabricate such a high aspect ratio core fiber is also provided.

Barbell optical fiber and method of making the same

According to an embodiment of the disclosure, a system for producing a higher power laser beam is provided. The system includes an optical fiber having a length. The optical fiber is configured to receive inputs from multiple laser pumps and an input from a Stokes seed laser pump. The optical fiber has a core that is doped. The core, when viewed from a cross-section of the optical fiber, has a higher concentration of doping at a location near an axis of the optical fiber than a location further from the axis of the optical fiber. The optical fiber is also configured to convert pump power to Stokes power along the length of the optical fiber when subjected to a Stimulated Raman Scattering (SRS) process.

Method and apparatus for high-power raman beam-combining in a multimode optical fiber

A method includes accumulating optical pump power in a first laser gain medium during a first period of time, where the first laser gain medium is optically located within a resonator. The method also includes providing at least some of the accumulated optical pump power as a first laser output with a feedback-controlled waveform from the first laser gain medium to a second laser gain medium during a second period of time, where the second period of time is substantially shorter than the first period of time. The method further includes generating a second laser output having a burst of laser pulses using the second laser gain medium as a power amplifier. The first and second laser outputs have higher power levels during the second period of time compared to a power level of the optical pump power during the first period of time.

Method and apparatus for temporally concentrating pump power to support generation of high peak-power pulse bursts or other time-varying laser output waveforms

The present disclosure is directed to electromagnetic radiation sensors including micro-lenses and to methods of constructing and utilizing such electromagnetic radiation sensors. In one embodiment there is provided an electromagnetic radiation sensor comprising a dielectric substrate including a front surface and a rear surface, an electromagnetic radiation detector element disposed on the rear surface of the substrate, and a lens comprising a three dimensional polaritonic metamaterial structure including a pattern of features formed in the front surface of the substrate, the lens configured to focus electromagnetic radiation incident on the front surface of the substrate onto the electromagnetic radiation detector element.

Sensor including dielectric metamaterial microarray

According to an embodiment of the disclosure, a Raman generator includes a Raman medium and one or more optical elements. The Raman medium is configured to receive a pump pulse at a first wavelength and shift at least a portion of the pump pulse energy or power into a Stokes-shifted pulse at a second wavelength. The one or more optical elements are configured to synchronize one or more subsequent passages of the Stokes-shifted pulse through the Raman medium with one or more subsequent pump pulses at the first wavelength. The synchronized passage of the Stokes-shifted pulse and one or more subsequent pump pulses through the Raman medium increases a power of the Stoke-shifted pulse.

Compact raman generator with synchronized pulses

A planar laser gain medium and laser system. The novel laser gain medium includes an active core having a high aspect ratio cross-section with a fast-axis dimension and a slow-axis dimension, signal claddings adapted to form reflective boundaries at fast-axis boundaries of the core, and a material adapted to minimize reflections at slow-axis boundaries of the core. In an illustrative embodiment, the laser gain medium is an optical fiber. The core and claddings for a waveguide adapted to control modes propagating in the fast-axis direction. When the laser gain medium is employed as a laser oscillator, a high reflectivity mirror and an outcoupler are positioned at opposite ends of the core to form a laser resonator adapted to control modes in the slow-axis direction.

Multi-sectional fiber laser system with mode selection

A system includes a laser configured to generate a pump beam at a pump wavelength. The system also includes a multi-media Raman resonator configured to receive the pump beam and generate an output beam. The multi-media Raman resonator includes multiple mirrors and multiple Raman media optically located between the minors. Output power in the output beam is spectrally concentrated around a single dominant wavelength that is longer than a pump wavelength. The longer wavelength of the output beam is associated with a combination of at least one Stokes shift associated with each of the individual Raman media. A filter could be configured to absorb light at a wavelength that is absorbed by one of the Raman media or to redirect light at the wavelength absorbed by one of the Raman media away from that Raman medium.

Multi-media raman resonators and related system and method

In various embodiments, an optical element, e.g., an optical fiber, may be configured to compensate for thermal lensing. For example, thermal lensing may be caused by light power dissipation within an optical fiber, which may include a fiber core that guides amplified light along the longitudinal dimension of the fiber core. Thermal lensing from a thermally induced change in material refractive index as a function of position along dimensions perpendicular to the fiber's longitudinal dimension may be at least partially compensated or offset when light is guided by the fiber core by a designed-in effective refractive index profile selected such that the designed-in material refractive index of the fiber core changes as a function of transverse position within the fiber core, or by selection of a favorable cross-sectional core shape in a plane perpendicular to the longitudinal dimension of the fiber core.

Growing community of inventors

San Pedro, CA, United States of America

Vladimir V Shkunov