Design and Monte Carlo-based accuracy analysis: a full-Stokes, division-of-amplitude, thin-film lithium niobate polarimeter

Polarization measurement is critical for photonic applications. With the advancement of low-cost, high-density multifunctional photonic integrated circuits (PICs), polarimeters that can be integrated with other on-chip devices have become increasingly attractive. In this paper, a full-Stokes, division-of-amplitude polarimeter based on thin-film lithium niobate (TFLN) was proposed, which primarily consists of adiabatic components, exhibiting the potential for low insertion loss and low wavelength dependence. In addition, via the Monte Carlo method, the influence of shot noise on the polarization detection accuracy of the TFLN polarimeter was quantitatively investigated for the first time, to the best of our knowledge, and the theoretical accuracy was estimated under different noise levels. According to simulations, at the wavelength of 1550 nm, when <i>n</i><i>o</i><i>i</i><i>s</i><i>e</i>=0.2<i>d</i><i>B</i>, the precision of Stokes vectors <i>S</i>₁, <i>S</i>₂, and <i>S</i>₃ and the root-mean-square error (RMSE) of the degree of polarization (DOP) can reach ∼[-0.0634,0.0634], ∼[-0.1002,0.1002], ∼[-0.0997,0.0997], and ∼0.048, respectively, within the fabrication tolerance of ±50<i>n</i><i>m</i>.