Domestic Fiber Bragg Grating Patents

Recent domestic patents on Fiber Bragg Gratings cover multicore optical fibers, multi-axis sensing systems, and advanced laser inscription methods. Key Patents and Technologies1.

Multicore Optical Fiber and Gain-

Flattening Gratings US20190041575A1 describes a multicore optical fiber (MCF) with fiber Bragg gratings (FBGs) used for gain flattening in long-haul optical communication systems. The patent details methods for inscribing gratings using ultraviolet lasers, including phase mask and interference exposure techniques, to achieve uniform refractive index modulation across multiple cores. This technology addresses issues like ripple width in transmission spectra and improves reproducibility and manufacturing efficiency for multicore slanted fiber gratings (MC-SFGs) in erbium-doped fiber amplifiers (EDFAs) for C-band and L-band transmission.

2.

Multi-

Axis Fiber Bragg Grating Sensors US20250258048 focuses on multi-axis FBG sensor systems for measuring forces in three dimensions. The system uses spatially distributed, mechanically isolated sensing towers with nonparallel pillars supporting FBGs. An interrogator captures wavelength shifts to measure multi-axis forces, enabling tactile sensing in robotics and harsh environments.

This patent highlights the application of FBGs beyond communication, emphasizing strain and force sensing with high durability and immunity to electromagnetic interference. 3. Femtosecond Laser Inscription in Optical Waveguides US20230194775A1 introduces a method for inscribing FBGs using ultrashort femtosecond laser pulses and diffractive optical elements or phase masks.

This approach allows precise modification of the refractive index in the fiber core, enabling high-resolution quasi-distributed temperature and strain sensing. The method enhances sensitivity, multiplexing capability, and EMI immunity, making it suitable for advanced sensing applications in industrial and scientific environments. 4.

Fiber Bragg Grating Position and Shape Sensing Additional patents, such as those summarized in Patsnap Eureka, describe FBG arrays in single-core or multicore fibers for position and shape sensing. These devices use broadband reference reflectors and frequency domain reflectometry to measure strain and local bending, enabling accurate determination of object shape or motion.

Summary of Trends

Multicore FB

Gs improve optical communication performance and allow simultaneous grating formation in multiple cores.

Multi-axis FB

G sensors expand applications into robotics, structural health monitoring, and tactile sensing. Advanced laser inscription techniques (femtosecond pulses, phase masks) enhance precision, sensitivity, and multiplexing. Integration with optical amplifiers and sensing systems demonstrates the dual role of FBGs in both communication and measurement technologies.

These patents collectively illustrate the domestic innovation landscape for FBGs, highlighting both manufacturing methods and diverse applications in sensing and optical networks.