Diffraction characteristics of radiated tilted fiber grating and its spectrometer application

Area of Science:

• Optics and Photonics
• Fiber Optic Devices
• Diffraction Gratings

Background:

• Fiber Bragg gratings are crucial optical components.
• Radiated tilted fiber gratings (RTFGs) offer unique diffraction properties.
• Understanding RTFG characteristics is key for advanced optical systems.

Purpose of the Study:

• To numerically and experimentally investigate the diffraction characteristics of RTFGs.
• To analyze the impact of tilt angle on RTFG performance metrics.
• To explore RTFG applications in spectral analysis and optical communications.

Main Methods:

• Numerical simulation of RTFG transmission spectra for various tilt angles (25°–54°).
• Experimental validation of simulated diffraction characteristics.
• Fabrication and testing of a miniaturized spectrometer using an RTFG.

Main Results:

• Larger tilt angles increase 3dB bandwidth (up to 301 nm at 54°).
• Maximum degree of polarization (DOP) of 0.998 achieved at 45° tilt.
• Smaller tilt angles improve angular dispersion; ultra-low temperature crosstalk observed.

Conclusions:

• RTFG performance (bandwidth, polarization, dispersion) is highly dependent on tilt angle.
• RTFGs exhibit ultra-low temperature crosstalk, suitable for stable optical systems.
• Proposed RTFG is ideal for in-fiber diffraction, with applications in spectrometers, optical communication, and Lidar.