A double-exposure fabrication method without any intensity shadow mask to fabricate arbitrarily apodized fiber Bragg gratings（ FBGs） with narrow bandwidth is demonstrated by controlling the total ultra violet （UV）...A double-exposure fabrication method without any intensity shadow mask to fabricate arbitrarily apodized fiber Bragg gratings（ FBGs） with narrow bandwidth is demonstrated by controlling the total ultra violet （UV） irradiation along the grating by varying the speed of a translation stage. The UV source used is a stable continuous intracavity frequency-doubled argonion laser. The parameters （such as length, apodization profile, average index change）of FBGs can be easily changed with this method. The total UV irradiation is kept constant in the doubleexposure process because of the precise control of the exposure time, which ensures that the apodized FBG＇s bandwidth can be extremely narrow. The full width at half maximum （FWHM） bandwidth of the 2-cm-long apodized FBG fabricated by this method is 0. 15 nm with a maximum reflectivity of more than 95%.展开更多
基金The Natural Science Foundation of Jiangsu Province(No.BK2004207)
文摘A double-exposure fabrication method without any intensity shadow mask to fabricate arbitrarily apodized fiber Bragg gratings（ FBGs） with narrow bandwidth is demonstrated by controlling the total ultra violet （UV） irradiation along the grating by varying the speed of a translation stage. The UV source used is a stable continuous intracavity frequency-doubled argonion laser. The parameters （such as length, apodization profile, average index change）of FBGs can be easily changed with this method. The total UV irradiation is kept constant in the doubleexposure process because of the precise control of the exposure time, which ensures that the apodized FBG＇s bandwidth can be extremely narrow. The full width at half maximum （FWHM） bandwidth of the 2-cm-long apodized FBG fabricated by this method is 0. 15 nm with a maximum reflectivity of more than 95%.
