## 1 Introduction
In contrast, laser-induced polarization switching has been ex  
Figure 1: The principle of the operation of self-activating laser protection systems: **(a)** an attenuator/optical switch; **(b)** a power limiter; **(c,d)** a sketch of the setup and the geometry of TN-textured NLC cell intended for the experimental investigation of NLC optical power limiters: (from left to right) continuous-wave laser (\(\uplambda=532\) nm), polarizer (P, 0\({}^{\circ}\)), twisted nematic NLC cell, polarizer (P, 90\({}^{\circ}\)), detector/CCD camera. **(e)** Light transmission as a function of the beam power for a TN-textured 6 CHBT NLC with a thickness of 12 μm (triangles), 50 μm (diamonds), and 75 μm (circles)—dark to light gray lines, respectively, according to the configuration shown in **(c)**, serve as a visual guide for the eye. **(f)** A plot of Sudan Blue II absorption versus wavelength for different dye concentrations (\(w/w\)): 0.1%, 0.2%, and 1.0% (light to dark blue lines, respectively). **(g)** Light transmittance as a function of the input beam power for a TN-textured 6 CHBT NLC doped with 1% \(w/w\) of Sudan Blue II dye: an average value plotted for NLC cells of a thickness 12 μm and 30 μm—light and dark blue lines, respectively. The black dots indicate experimental data for six analyzed cells in 8 different areas, and the shaded regions represent a standard deviation of the mean value. plored in dye-doped nematic liquid crystals (LCs) for passive all-optical switching at the microsecond time scale and beyond. The aforementioned materials and techniques diverge based on the scope of the intensities at which the impact of limiting the intensity of the transmitted beam is observed. Furthermore, these methods differ in terms of their response times and the extent to which the solution can be implemented. Liquid crystals are widely recognized as a fascinating class of responsive soft materials that hold a unique position between isotropic liquids and crystalline solids [7; 32; 33; 34; 35; 36]. Typical nematic liquid crystals (NLCs) exhibit broad spectral sensitivity (UV-mid-IR) and significant birefringence (\(\Delta\)n = ne \(-\) no \(\approx\) 0.1-0.5) [37]. They possess both the fluidity of liquids and the ordered structure of solids at various levels, resulting in a diverse range of phases dependent on their components' level of orientational order. These mesophases have gained much attention in both practical applications and fundamental research. Furthermore, numerous intriguing nonlinear optical phenomena have been observed in different liquid crystalline materials [37; 38; 39], demonstrating their unique order, dynamics, and optical properties, making them promising candidates for intelligent self-activating optical limiters [12; 33; 40; 41; 42]. The extensive availability of diverse liquid crystal compounds, coupled with the well-established technology for manufacturing NLC-based devices, presents an opportunity for these materials to occupy a market niche in specific applications for the protection of optoelectronic devices, such as CCD arrays and photodetectors. Of particular interest are the all-optical switching phenomena observed in LCs, which have continuously captured attention due to their potential applications in integrated photonic circuits and optical limiting devices [43; 44; 41]. The primary aspect crucial for these applications is the induction of birefringence through optical means. Investigations have demonstrated that dye-doped nematic LCs achieve low-threshold polarization switching and optical limiting for continuous-wave and microsecond lasers [43]. Subsequent analysis has attributed this phenomenon to the modification of the order parameter induced by laser beam heating [45]. The current state of the art in optical power limiters based on liquid crystals includes research on liquid crystal optical fibers, switchable contact lenses, laser damage resistance of liquid crystal devices, and plasmonic metasurfaces for hydrogen detection.