A novel fabrication method for corrugated long-period fiber gratings (CLPFG) is presented in this study. The patterned SU-8 photoresist is used as a double-side stopper layer for a wet-etching process to fabricate the CLPFG. Presented in this research are four types of CLPFG with periods of 660, 670, 680, and 690 µm and resonant wavelengths of 1531, 1539, 1550, and 1558 nm, respectively. The maximum resonance loss of the CLPFG with a 680-µm period is 23 dB. The CLPFG fabricated in this study is demonstrated for temperature sensing, and the results illustrate that the fabricated CLPFG with a 680-µm period has a temperature sensitivity of 58.4 pm/°C, a wavelength-shifting linearity of R2=0.994, and a 0.856 °C resolution.
This study presents a novel fabrication method of corrugated long-period fiber gratings (CLPFG). The chemical
wet etching process is used to fabricate the CLPFG, and the patterned SU-8 50 photoresist is used as etch mask. Since the
CLPFG fabricated by the novel method reduces the complication and cost, it is suitable for mass production. In this study,
the period of the CLPFG is 690 μm and the resonant-attenuation wavelength is 1558 nm. The maximum
resonance-attenuation of the CLPFG is 23 dB. Eventually, the CLPFG in this study has demonstrated a high temperature
sensitivity (60 pm/ °C), wavelength-shifting linearity (R2=0.99), and 1°C of resolution.