Numerical studies of modal instabilities in high-power fiber amplifiers

Shadi Naderi; Iyad Dajani; Timothy Madden; Bemjamin Ward; Craig Robin; Jake Grosek

doi:10.1117/12.2006571

22 March 2013 Numerical studies of modal instabilities in high-power fiber amplifiers

Shadi Naderi, Iyad Dajani, Timothy Madden, Bemjamin Ward, Craig Robin, Jake Grosek

Proceedings Volume 8601, Fiber Lasers X: Technology, Systems, and Applications; 86013F (2013) https://doi.org/10.1117/12.2006571
Event: SPIE LASE, 2013, San Francisco, California, United States

Abstract

We present a detailed time-dependent numerical model of the modal instability phenomenon observed in Yb-doped fiber amplifiers. The thermal effects are captured by solving the heat equation in polar coordinate using a 2D, second-order, time-dependent, alternating direction implicit (ADI) method. The model captures the three power-dependent regions that are characteristic of the transfer of energy between the fundamental mode and the higherorder mode as a function of time. It is also shown that for the fiber configuration investigated, the modal instability threshold scales linearly over a wide range with the seed power. Furthermore, we present numerical results indicating that gain tailoring can increase the threshold. Two different gain-tailored fiber designs are simulated and compared.

Citation Download Citation

Shadi Naderi, Iyad Dajani, Timothy Madden, Bemjamin Ward, Craig Robin, and Jake Grosek "Numerical studies of modal instabilities in high-power fiber amplifiers", Proc. SPIE 8601, Fiber Lasers X: Technology, Systems, and Applications, 86013F (22 March 2013); https://doi.org/10.1117/12.2006571

ACCESS THE FULL ARTICLE

INSTITUTIONAL
Select your institution to access the SPIE Digital Library.

SELECT YOUR INSTITUTION

PERSONAL
Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.

PERSONAL SIGN IN

No SPIE Account? Create one

PURCHASE THIS CONTENT

SUBSCRIBE TO DIGITAL LIBRARY

50 downloads per 1-year subscription

Members: $195

Non-members: $335 ADD TO CART

25 downloads per 1 - year subscription

Members: $145

Non-members: $250 ADD TO CART

PURCHASE SINGLE ARTICLE

Includes PDF, HTML & Video, when available