We demonstrate a novel all-fiber gap-type tunable bandpass filter configuration that consists of a broadband hollow optical fiber (HOF) acoustooptic tunable filter (AOTF) concatenated with a narrowband single-mode fiber (SMF)-AOTF. Owing to the unique mode coupling properties of HOF-AOTF and SMF-AOTF, a narrow passband channel of a full-width at half-maximum (FWHM) of ∼4 nm could be formed in a broad stopband platform of a 90-nm FWHM successfully. In this scheme, the center wavelength and rejection efficiency of both passband and stopband were found to be flexibly tunable by adjusting the frequency and the voltage of radio-frequency signals applied to individual acoustic transducers.
Bibliographical noteFunding Information:
Manuscript received April 2, 2007; revised June 7, 2007. This work was supported in part by the KOSEF (Program R01-2006-000-11277-0 and Program R15-2004-024-00000-0), and in part by the KICOS (Program 2007-8-0536). Y. Jung and B. H. Lee are with the Department of Information and Communications, Gwangju Institute of Science and Technology (GIST), Gwangju 500-712, Korea. S. B. Lee is with the Communication and Cable Group, Digital TV Research Laboratory, LG Electronics, Seoul 151-818, Korea. K. Oh is with the Institute of Physics and Applied Physics, Yonsei University, Seoul 120-749, Korea (e-mail: email@example.com). Color versions of one or more of the figures in this letter are available online at http://ieeexplore.ieee.org. Digital Object Identifier 10.1109/LPT.2007.902917
All Science Journal Classification (ASJC) codes
- Electronic, Optical and Magnetic Materials
- Atomic and Molecular Physics, and Optics
- Electrical and Electronic Engineering