Miniature Fourier Transform Spectrometer Based on Thin-Film Lithium Niobate

• Published in: Micromachines (Basel) Vol. 14; no. 2; p. 458
• Main Authors: Zhang, Lichao, Gou, Guangyang, Chen, Jiamin, Li, Wangzhe, Ma, Weichao, Li, Ruoming, An, Junming, Wang, Yue, Liu, Yuanyuan, Yan, Wei, Ma, Tianjun, Liu, Chunxiu, Cheng, Jianjun, Qi, Zhimei, Xue, Ning
• Format: Journal Article
• Language: English
• Published: Switzerland MDPI AG 15.02.2023; MDPI
• Subjects: Analysis; Design; Dielectric films; Electric potential; electro-optical modulation; Electrodes; Etching; Fourier transform spectrometer; Fourier transform spectrometers; Fourier transforms; Gold; Lithium; Lithium niobate; Lithium niobates; Optical waveguides; Optics; Signal processing; Silicon nitride; Simulation; Thin films; Voltage; Waveguides; China; electro-optical modulation; lithium niobate; Fourier transform spectrometer
• ISSN: 2072-666X; 2072-666X
• DOI: 10.3390/mi14020458

A miniature Fourier transform spectrometer is proposed using a thin-film lithium niobate electro-optical modulator instead of the conventional modulator made by titanium diffusion in lithium niobate. The modulator was fabricated by a contact lithography process, and its voltage-length and optical waveguide loss were 2.26 V·cm and 1.01 dB/cm, respectively. Based on the wavelength dispersion of the half-wave voltage of the fabricated modulator, the emission spectrum of the input signal was retrieved by Fourier transform processing of the interferogram, and the analysis of the experimental data of monochromatic light shows that the proposed miniaturized FTS can effectively identify the input signal wavelength.