Abstract:
The output spectrum characteristics of a linearly chirped fiber Bragg grating (LCFBG) under localized point heating with different heating temperatures, widths and positions were investigated. The numerical simulation shows that the heating temperature and heating width applied onto the LCFBG have an obvious influence on the transmissivity and central wavelength of narrow-band transmission peaks in the transmission bandgap. The central wavelengths of the transmission peaks have a good linear relationship with the local heating positions of the LCFBG and can shift in the whole transmission bandgap region. The chirp coefficient of the LCFBG determines the wavelength tuning velocity of the transmission peaks induced by the change in the heating position. Based on the theoretical results, the spectral characteristics of the LCFBG are investigated experimentally using a commercial thermal printhead as a local heating source. The narrow-band transmission peaks are realized with high performance in terms of reproducibility, stability and potential multiwavelength tunability. The experimental results are in good agreement with those of the numerical simulation within the experimental error.