Thulium-doped fiber performance optimization via fiber bending and twisting and inner-cladding shape design

Result code in IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F68407700%3A21340%2F21%3A00367190" target="_blank" >RIV/68407700:21340/21:00367190 - isvavai.cz</a>

Result on the web

<a href="https://doi.org/10.1117/12.2592309" target="_blank" >https://doi.org/10.1117/12.2592309</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1117/12.2592309" target="_blank" >10.1117/12.2592309</a>

Result language

angličtina

Original language name

Thulium-doped fiber performance optimization via fiber bending and twisting and inner-cladding shape design

Original language description

Thulium-doped fiber lasers have been extensively investigated as the most promising source of efficient laser emission at wavelengths around 2 μm, i. e., in the eye-safer spectral region and in the atmospheric window as well. It allows for wide range of applications including medicine, defense, distance measurement or materials processing. To enhance pump absorption efficiency along the active double-clad fiber, good overlap of the pump light and doped fiber core should be achieved along the fiber length. The overlap can be increased by breaking the circular symmetry of the inner cladding by shaping its cross-section. Further mode-mixing and better pump absorption can be achieved by coiling and twisting of double-clad fibers. In this work we present experimental measurement of 792 nm pump cladding absorption of a series of double-clad thuliumdoped fibers with respect to their bend radius, the inner cladding cross-sectional shape and twist rate. With these fibers, we assembled a set of fiber lasers with different resonator setups and tested their performance. Twisting was introduced to fiber during drawing from an octagonal, CO2 laser-shaped or mechanically grinded preform so that the twist remained frozen in the drawn fiber. We have shown that the fiber twist significantly improves the pump absorption even in the case of straight or coiled fibers with large coil radii. We provide a preliminary comparison of two fiber laser resonators.

Czech name

—

Czech description

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Type

D - Article in proceedings

CEP classification

—

OECD FORD branch

10306 - Optics (including laser optics and quantum optics)

Project

—

Continuities

S - Specificky vyzkum na vysokych skolach<br>I - Institucionalni podpora na dlouhodoby koncepcni rozvoj vyzkumne organizace

Publication year

2021

Confidentiality

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů

Article name in the collection

Proc. SPIE 11773, Micro-structured and Specialty Optical Fibres VII

ISBN

978-1-5106-4380-2

ISSN

0277-786X

e-ISSN

1996-756X

Number of pages

6

Pages from-to

—

Publisher name

SPIE

Place of publication

Bellingham (stát Washington)

Event location

Praha

Event date

Apr 19, 2021

Type of event by nationality

WRD - Celosvětová akce

UT code for WoS article

000696183900029