Chiral Long Period Grating with Etched Multi-Core Fiber

We have demonstrated a long period grating manufacture with multi-core fiber which being heated with CO
₂
laser while being rotated by stepping motor. When the pitch of the grating is 900um, the wavelength with the coupling occurred between modes is given out at 1255.33nm, 1327.33nm, 1396.66nm, 1556.667nm. We put this long period grating in different environment with different refractive index and it shows sensitivity to environment refractive index. Furthermore, the sensitivity of temperature is about 7.7pm/°C.