Long period polymer waveguide grating device with positive temperature sensitivity

A long-period waveguide grating (LPWG) was demonstrated in a low-loss negative tone UV-sensitive epoxy novolak resin polymer. The grating structure was fabricated on top of the waveguide using a standard UV lithography process, and no other subsequent process is required after the development step. It is shown that with an appropriate design of the structure a transmission peak at the desired wavelength can be achieved. The LPWG exhibits an attenuation of -18 dB using a grating length of 17 mm. The temperature sensitivity of the LPWG is linear and is found to be ∼ 0.89 nm/°C. A red shift of the transmission peak wavelength was also observed and is discussed.