Ultrashort Long-Period Fiber Grating Sensors Inscribed on a Single Mode Fiber Using Laser Radiation

Figure 4

Micrograph showing the tapering effect in the irradiated zones in a 2.4 mm LPFG with 600 μm period written on an SMF-28 optical fiber ( ≈ 4.5 W; = 0.6 s; ≈ 0.78 N).