Vol. 42, Issue 4, pp. 751-759 (2012)

Abstract

A novel identical multiple wavelength sampled fiber Bragg grating (FBG) is proposed. A phase shift between the two adjacent FBG units is achieved by increasing the direct current (DC) refractive index of the FBG. The FBG with identical reflective spectrum is optimized with a designed sampling function. DC phase shift FBGs are analyzed and fabricated, which shows a good agreement with a discrete phase shift method. A dual-wavelength (DW) filter with channel spacing 0.16 nm is fabricated, and the experiment results verified the feasibility of this proposed method. A four-wavelength filter with channel spacing 0.16 nm is then proposed and demonstrated. This method has the following advantages: wavelength design is flexible, fabrication precision and costs are low.