Bandpass filters based on π-shifted long-period fiber gratings for actively mode-locked erbium fiber lasers

Abstract

We have fabricated bandpass filters based on $\pi$-shifted long-period gratings for application in actively mode-locked erbium fiber lasers. Introducing the $\pi$-phase shift in the middle of the grating opens a bandpass within the core–cladding mode resonance peaks. With a 22-nm bandwidth filter inserted in an actively mode-locked erbium fiber sigma laser, solitonlike pulses are generated, with a power-dependent duration of $\approx 3–5 \mathrm{ps}$, at a 3-GHz repetition rate. These all-fiber filters have the advantages of low insertion loss $\left(<0.5 \mathrm{dB}\right)$ and a wide bandwidth (10–20  nm), and they do not require that a circulator be inserted into the laser cavity.

© 2001 Optical Society of America

Band-selection filters with concatenated long-period gratings in few-mode fibers

Siddharth Ramachandran, Samir Ghalmi, Zhiyong Wang, and Man Yan
Opt. Lett. 27(19) 1678-1680 (2002)

Wide-passband, temperature-insensitive, and compact π-phase-shifted long-period gratings in endlessly single-mode photonic crystal fiber

Yinian Zhu, Ping Shum, Hui-Wen Bay, Xiaoyan Chen, Ching-Hwee Tan, and Chao Lu
Opt. Lett. 29(22) 2608-2610 (2004)

Erbium-doped fiber laser simultaneously mode locked on more than 24 wavelengths at room temperature

J.-N. Maran, S. LaRochelle, and P. Besnard
Opt. Lett. 28(21) 2082-2084 (2003)

Resonance-temperature-insensitive phase-shifted long-period fiber gratings induced by surface deformation with anomalous strain characteristics

Yinian Zhu, Ping Shum, Xiaoyan Chen, Ching-Hwee Tan, and Chao Lu
Opt. Lett. 30(14) 1788-1790 (2005)

Ultra-wide bandpass filter based on long-period fiber gratings and the evanescent field coupling between two fibers

Myoung Jin Kim, Yong Min Jung, Bok Hyeon Kim, Won-Taek Han, and Byeong Ha Lee
Opt. Express 15(17) 10855-10862 (2007)