The Resonant Bandwidth Enhancement in a Mechanically Induced Long Period Fiber Grating Formed over a Twisted Fiber.

Autor: Kumar, V. P. Sudeep, Nair, B. Unnikrishnan, Pillai, V. P. Mahadevan, Nayar, V. U.
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Zdroj: Fiber & Integrated Optics; Nov2007, Vol. 26 Issue 6, p343-351, 9p, 1 Diagram, 5 Graphs
Abstrakt: A mechanically induced grating formed over a twisted fiber can increase the resonant bandwidth. The tunability and control of the resonant bandwidth is found to be dependent on the induced twist. The effective group indices of cladding modes increase with the twist-induced birefringence. The difference in group indices between the LP01 and the cladding modes LP11, LP12, and LP13 decreases as the fiber twist rate increases above 0.5 turns/cm. This results in bandwidth enhancement of the grating. This broadband mode converter, which has a wide tunability, is cost effective and insensitive to pressure-induced birefringence. The resonant bandwidth can be increased and tuned further by forming two gratings in series with a twist-free and twisted fiber portions. A coupling bandwidth of around 100 nm (< 3 db) is achieved in this dual grating technique. [ABSTRACT FROM AUTHOR]
Databáze: Complementary Index