8-W coherently phased 4-element fiber array

Jesse Anderegg; Stephen John Brosnan; Mark E. Weber; Hiroshi Komine; Michael G. Wickham

doi:10.1117/12.478311

3 July 2003 8-W coherently phased 4-element fiber array

Jesse Anderegg, Stephen John Brosnan, Mark E. Weber, Hiroshi Komine, Michael G. Wickham

Proceedings Volume 4974, Advances in Fiber Lasers; (2003) https://doi.org/10.1117/12.478311
Event: High-Power Lasers and Applications, 2003, San Jose, CA, United States

Abstract

A four-element fiber array has been constructed to yield 8 watts of coherently phased, linearly polarized light energy in a single far field spot. Each element consists of a 2-W single-mode fiber-amplifier chain. Phase control of each element is achieved with a lithium-niobate phase modulator. A master laser provides a linearly polarized, narrow linewidth signal that is split into five channels. Four channels are individually amplified using polarization maintaining fiber power amplifiers. Frequency broadening of the signal is necessary to avoid stimulated Brillouin scattering. The fifth channel is used as a reference arm. It is frequency shifted and then combined interferometrically with a portion of each channel's signal. Detectors sense the heterodyne modulation signal, and an electronics circuit measures the relative phase for each channel. Compensating adjustments are then made to each channel's phase modulator. The stability of the optical train is an essential contributor to its success. A state-of-the-art interferometer was built with mountless optics. A lens array was constructed using nano-positioning tolerances, where each lens was individually aligned to its respective fiber to collimate its output and point it at a common far field spot. This system proved to be highly robust and handled any acoustic perturbations.

Citation Download Citation

Jesse Anderegg, Stephen John Brosnan, Mark E. Weber, Hiroshi Komine, and Michael G. Wickham "8-W coherently phased 4-element fiber array", Proc. SPIE 4974, Advances in Fiber Lasers, (3 July 2003); https://doi.org/10.1117/12.478311

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