A rectangular-core fiber that guides and amplifies a higher-order-mode can potentially scale to much higher average powers than what is possible in traditional circular core large-mode-area fibers. Such an amplifier would require mode-conversion at the input and output to enable interfacing with TEM₀₀ mode seed sources and generate diffraction-limited radiation for various applications. We discuss the simulation and experimental results of a mode conversion technique that uses two diffractive-optic-elements in conjugate Fourier planes to convert a diffraction limited TEM₀₀ mode to the higher-order-mode of a ribbon core fiber. Our experiments show that the mode-conversion-efficiency exceeds 84% and can theoretically approach 100%.

Date Published: 7 May 2012
PDF: 6 pages
Proc. SPIE 8381, Laser Technology for Defense and Security VIII, 838103 (7 May 2012); doi: 10.1117/12.920769

Published in SPIE Proceedings Vol. 8381:
Laser Technology for Defense and Security VIII
Mark Dubinskii; Stephen G. Post, Editor(s)