Tilted superstructure fiber grating used as a Fourier-transform spectrometer

Area of Science:

• Photonics and Optical Engineering
• Spectroscopy
• Fiber Optics

Background:

• Traditional spectrometers can be bulky and complex.
• Integrating spectroscopic functionality directly into fiber optic systems presents challenges.
• Developing compact, high-precision optical sensing devices is crucial for various applications.

Purpose of the Study:

• To propose and demonstrate a novel method for fabricating a compact all-fiber spectrometer.
• To utilize a tilted superstructure fiber grating for efficient light coupling and spectral analysis.
• To achieve high-precision wavelength measurements within a fiber optic platform.

Main Methods:

• Fabrication of a compact all-fiber spectrometer using a tilted superstructure fiber grating.
• Coupling light out of a fiber core to generate a near-field interference pattern.
• Applying Fourier transform to the interference pattern for direct optical input spectrum measurement.

Main Results:

• Demonstrated a compact all-fiber spectrometer with a novel grating design.
• Achieved picometer-level precision for single-wavelength measurements over an 80-nm range.
• Enabled coarser precision measurements over a broader 160-nm range.
• Superstructure grating design allows control over spectrometer resolution and bandwidth.

Conclusions:

• The proposed method offers a new pathway for creating compact and high-performance fiber spectrometers.
• The tilted superstructure fiber grating is effective for spectral analysis within a fiber.
• This technology has potential for advanced optical sensing and measurement applications.