Miniature Fourier Transform Spectrometer Based on Thin-Film Lithium Niobate.

Area of Science:

• Photonics and Optical Engineering
• Materials Science
• Spectroscopy

Background:

• Conventional Fourier transform spectrometers (FTS) often rely on bulky or complex modulator designs.
• Titanium diffusion in lithium niobate is a common, yet potentially limiting, method for fabricating modulators.

Purpose of the Study:

• To propose and demonstrate a miniaturized Fourier transform spectrometer (FTS).
• To utilize a thin-film lithium niobate electro-optical modulator for enhanced FTS performance.

Main Methods:

• Fabrication of a thin-film lithium niobate electro-optical modulator using contact lithography.
• Characterization of modulator performance, including voltage-length product and optical waveguide loss.
• Retrieval of emission spectra by Fourier transform processing of interferograms based on wavelength dispersion.

Main Results:

• The fabricated modulator achieved a voltage-length product of 2.26 V·cm and an optical waveguide loss of 1.01 dB/cm.
• The device successfully retrieved the emission spectrum of an input signal.
• Experimental data confirmed the FTS's ability to effectively identify monochromatic light wavelengths.

Conclusions:

• A miniaturized FTS using a thin-film lithium niobate modulator is feasible and effective.
• This approach offers a compact and efficient alternative for spectral analysis.
• The technology shows potential for various applications requiring precise wavelength identification.