## 1 Introduction
Polarization dependency makes the scanners deflect the light if it is only polarized in a certain direction. Therefore, polarization dependency limits these scanners' application even in one dimension and makes it impossible to steer the light in two dimensions in one crystal. [PERSON] and [PERSON] et al. developed an EO scanner based on the Kerr effect and space-charge-controlled electrical conduction using paraelectric KTN [7; 25]. They heated a 0.5 mm thick small KTN single-crystal slab with uniform titanium electrodes up to a few degrees above its Curie temperature to inject electrons into the crystal, taking advantage of the crystal's high permittivity at around its Curie temperature [6]. They reported deflecting an 80 \(\upmu\)m beam to 125 mrad by applying 500 V/mm, resulting in less than 20 resolvable spots [7]. Although this scanner uses another physical effect besides the EO effect and has the lowest applied voltage reported so far, it has several limitations. First, KTN does not have an excellent transmission in near IR and mid-IR. Moreover, adjusting the temperature in this scanner is crucial to ensure the KTN is in its paraelectric region and the permittivity is high enough to inject the electrons. In addition, using a crystal at its maximum dielectric constant will result in high loss and slow response. Furthermore, because it is impossible to inject electrons in thick dielectrics, the crystal must always be a fraction of a millimeter thick or less, which significantly limits its beam size and number of resolvable spots. The structure of the scanner and its polarization dependency not only limit its ability to steer the beam to one dimension in many applications but also makes it impossible to steer the beam to both dimensions in one crystal. The only way to steer the light in two dimensions using this scanner is to steer the light to one dimension in a crystal first, then flip the polarization of the light by a halfwave plate and focus it on another crystal to steer it into the other dimension. This inefficient and lengthy procedure does not offer a compact two-dimensional beam steering, limits the deflection angle in both dimensions, and may cause beam clipping and distortion from hitting the crystal wall boundary. In addition to the index change, the deflection angle of an EO steerer depends on the effective length-to-width ratio of the EO crystal [1; 2; 13; 14; 24; 26]. Since long single EO crystals are usually not available, the crystals' effective width is reduced to increase the deflection angle in some studies. [PERSON] and [PERSON] suggested cutting the EO crystal like a fishtail [11]. [PERSON] et al. suggested a trapezoid-shaped and horn-shaped crystal to maximize the effective length-to-width ratio and maximize the deflection angle [24]. However, cutting and machining the EO crystal increases the cost of the EO beam steerer. Therefore, if a long EO medium were available, the optimum shape would be a long rectangular shape. Polycrystalline Pb(Mg\({}_{1/3}\)Nb\({}_{2/3}\))O\({}_{3}\)-PbTiO\({}_{3}\) (PMN-PT) exhibits a much higher EO effect compared to LiNbO\({}_{3}\) and LiTaO\({}_{3}\) and is transparent from visible to mid-IR. This ceramic is relatively inexpensive and available in a larger size [5,19]. In this study, the refractive index of polycrystalline PMN-PT was determined using the Fourier-transform infrared (FTIR) spectroscopy as well as its transmission over a wide range of optical frequencies. A capacitance bridge analysis was performed to characterize the effect of temperature on the dielectric constant of this ceramic as well. A polarization-independent beam steerer was designed using polycrystalline PMN-PT. Its performance was simulated using COMSOL Multiphysics and measured in the lab for the wavelengths of 532, 632.8, 1550, and 4500 nm. The quadratic Kerr EO coefficient and the halfwave electric field for each wavelength were determined by measuring the deflection angle and refractive index associated with each wavelength.