Fig. 1. Two-photon polymerization system based on femtosecond laser. (a) Two-photon polymerization system; (b) three-dimensional control platform; (c) processed microfiber

Fig. 2. Schematic diagram of microfiber long-period grating processing. (a) Single mode fiber; (b) tapering a microfiber; (c) coating IP-L; (d) laser processing; (e) washing away unreacted IP-L

Fig. 3. Sample transmission spectrum

Fig. 4. SEM structure diagram of microfiber long-period grating

Fig. 5. Temperature response of microfiber long-period grating

Fig. 6. Refractive index response of microfiber long-period grating