Nufern

Yale University

Peyman Ahmadi

Kanishka Tankala

Martin Seifert

Peter Rosenthal

Imtiaz Majid

Jaroslaw Abramczyk

Kevin Farley

Hui Cao

Clemence Jollivet

Brandon Redding

Michael Conroy

Eric Lim

Cyril Guintrand

Peter Andrew Rosenthal

A high-power fiber laser produces a compound output beam having a center beam and an annular beam. The center beam and the annular beam are independently adjustable in power and wavelength. The output beam is delivered from an output optical fiber having a center core and a concentric annular core. A fundamental beam generated by a seed laser is amplified by a fiber amplifier and partially converted to a second-harmonic beam by a second-harmonic generator. The residual fundamental beam and second-harmonic beam are separated, attenuated, and selectively coupled into the cores of the output optical fiber.

Multi-wavelength adjustable-radial-mode fiber laser

The present disclosure relates more particularly to active optical fibers, amplified spontaneous emission (ASE) sources using such active optical fibers, and imaging and detection systems and methods using such ASE sources. In one aspect, the disclosure provides an active optical fiber that includes a rare earth-doped gain core configured to emit radiation at at least a peak wavelength emitted wavelength when pumped with pump radiation having a pump wavelength; a pump core surrounding the gain core; and a cladding surrounding the pump core, wherein the value M=16R(NA)/&#x3bb;in which R is the gain core radius, NA is the active optical fiber numerical aperture, and &#x3bb; is the peak emitted wavelength, is at least 50, or at least 100. The present disclosure also provides an optical source that includes the optical fiber coupled to a pump source.

Sources of optical radiation and methods for providing low-speckle optical radiation, and systems and methods using them

The present disclosure relates more to mode mixing optical fibers useful, for example in providing optical fiber laser outputs having a desired beam product parameter and beam profile. In one aspect, the disclosure provides a mode mixing optical fiber that includes a core having a refractive index profile; and a cladding disposed about the core. The core of the mode mixing optical fiber supports at least two (e.g., at least five) guided modes at the wavelength. The mode mixing optical fiber is configured to substantially distribute optical radiation having the wavelength propagating therein (e.g., input at its input end or generated or amplified within the core) among a plurality of the guided modes (e.g., to distribute a substantial fraction of the optical radiation having the wavelength propagating therein from its lower-order guided modes to its higher-order guided modes).

Mode mixing optical fibers and methods and systems using the same

The present disclosure relates to methods and apparatuses for providing optical radiation having improved rise/fall times and improved levels of leakage. One method for amplifying optical radiation includes an intermediate stage () having an intermediate active optical fiber (), the intermediate active optical fiber and a final amplifying stage () including a final active optical fiber (), and providing optical radiation to the input of the intermediate active optical fiber, wherein one or more final optical pump sources () are together in a low power state such that the optical radiation is substantially absorbed by the intermediate active optical fiber and such that substantially no optical radiation of the amplified wavelength is transmitted by the intermediate stage. The intermediate active optical fiber () can then be switched to a transmissive state by switching the final optical pump source(s) () to a high power state. The input to the intermediate stage may comprise a seed laser () and plural first amplifier stages () having each a first active optical fiber (). A filter () between the intermediate stage () and the final amplifying stage () prevents ASE and pump light from the intermediate stage to reach the final amplifying stage.

Method and apparatus for providing amplified radiation

Methods and apparatuses for determining the polarization state and for providing polarization control in optical fiber lasers and amplifiers. One embodiment of the invention is an optical fiber amplifying system including a circulator () having a first optical port (), a second optical port () that is configured to output radiation received from the first optical port, and a third optical port () that is configured to output radiation received from the second optical port; one or more amplifier stages () connected in series, together having an optical input () optically coupled to the second port of the circulator, and an optical output (); and a polarization detector () having an optical input optically coupled to the third port of the circulator. Thereby the polarization state of the amplified radiation can be determined using radiation backscattered from the amplifying stage.

Method and apparatus for polarization determination and/or control in optical fiber amplifying systems

Growing community of inventors

Manchester, CT, United States of America

Peyman Ahmadi