Tunable filter based on cavity electro-optic modulation for DWDM applications

In this paper the authors have demonstrated the feasibility and the realization of a wavelength tunable filter with an electro-optic modulation effect realized on diffused Ti:LiNbO3 waveguide. The two reflectors of the cavity consist in two Bragg's mirrors of identical period Lambda = 1.81 mu m and whose total number N = 140. Both mirrors have been engraved using the Focused Ion Beam technique up to the depths l(1) = l(2) = 2.7 mu m separated by a distance of l(c) = 500 mu m. We obtained thanks to electro-optic modulation effect a tunable shift whose value is 0.67 nm in a free spectral range FSR = 1.59 am for a voltage variation up to 60 V. This designed and realized probe will find many DWDM (Dense Wavelength Division Multiplexing) applications. (C) 2014 Elsevier B.V. All rights reserved.