Open AccessSuppression of sidelobe levels using two cascaded single-stage acousto-optic tunable filters
Author(s) -
Wei Yang,
Ying Liu,
Xiao Li-Feng,
Shuli Gao
Publication year - 2009
Publication title -
wuli xuebao
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.199
H-Index - 47
ISSN - 1000-3290
DOI - 10.7498/aps.58.328
Subject(s) - optics , single stage , bandwidth (computing) , transfer function , polarization (electrochemistry) , stage (stratigraphy) , optical filter , materials science , filter (signal processing) , physics , computer science , telecommunications , chemistry , paleontology , electrical engineering , engineering , computer vision , biology , aerospace engineering
Transfer function of single-stage acousto-optic tunable filter (AOTF) has sidelobes higher than -9 dB, and this large sidelobes level limits AOTF application. In this paper, the sidelobes of two single-stage AOTF's, which are polarization-dependent collinear and polarization-independent quasi-collinear respectively, are investigated, and the transfer function of double-stage filter is obtained. The calculations on single- and double-stage AOTF's have shown that the double-stage device can provide significant improvement in sidelobe suppression. In experiment, two single-stage AOTF's are cascaded, and filtering property of this double-stage device is measured. The experimental results show that the sidelobes of this cascaded AOTF is suppressed to -19dBand the 3-dB bandwidth is narrowed to some outent.