Fast-tunable filters play a crucial role in various applications
including tunable lasers, high-speed optical communications, microwave
photonics, and spectroscopy. However, current fiber Fabry-Pérot
tunable filters (FFPTF) predominantly rely on piezoelectric transducers
(PZT), which struggle to achieve rapid modulation with high repeatability
and accuracy owing to hysteresis and creep effects. In this study,
we demonstrate an FFPTF with high linearity (>0.99) and an approximate
1 MHz dynamic tuning frequency in the resonant state using the thickness–shear
resonance of a Y-cut 163° lithium niobate (LiNbO3) sheet. The device exhibited a high overall performance with
a finesse of 118 and an insertion loss of 2.54 dB, with well-designed
fiber cavity configurations. This study provides a new approach for
precise and rapid wavelength manipulation and selection, thereby paving
the way for high-speed optical modulation and analyses.