A strain-induced birefringent double-clad fiber Bragg grating

A strain-induced birefringence double-clad (DC) fiber Bragg grating (FBG) is proposed and demonstrated. The grating is fabricated in the core of rectangular inner cladding double clad fiber by using phase mask method. By applying lateral strain on the grating, the birefringence is induced. In order to detect the birefringent effect of the grating, we use it as the output mirror of a laser. When lateral strain is applied, the grating becomes birefringent. Therefore, one reflection peak of double-