因利用传统等截面简支梁调谐光纤布拉格光栅会产生啁啾现象，设计了一种新型的等边菱形纯弯梁结构，本结构不会产生啁啾现象，其理论研究和实验研究一致。新型菱形梁可以实现裸纤(光纤布拉格光栅)8 nm 的调谐范围，调谐线性拟合度高达99.9%，调谐过程中光纤布拉格光栅3 dB 带宽无畸变。该纯弯梁具有良好的对称性，实现了光纤布拉格光栅的线性无啁啾调谐。

Because the simple beam of traditional equal section used for tuning fiber Bragg grating (FBG) can make the FBG produce chirp, a novel tuning structure utilizing the equilateral rhombic beam under pure bending is designed, which has no chirp appearing. The experimental research is consistent with theoretical research well. The novel rhombic beam can realize the tuning wavelength of 8 nm, the linearity of 99.9%. And the 3 dB reflection bandwidth shows no change during the tuning process. The beam under pure bending has good symmetry, which realizes the linearly chirp-free central wavelength tuning of FBG.<网络出版日期:>2015-12-18