VO₂ Film For Laser Protection

The rapidly developing laser weapons are important roles in wars. They could directly destroy targets or disturb the regular function of photoelectric devices, which was called laser blind jamming. Not much power was needed to cause laser blind to core component of infrared windows. The booming laser weapons push researchers concerning on laser protection.Vanadium dioxide(VO2) as a typical thermochromic material, with its photo-induced metal-to-insulator transition(MIT) feature, has been widely researched in material physics. With the advantage of low transition threshold, high damage threshold and the ultrashort MIT time, VO2 is regarded as a promising material for laser protection. when the temperature is below 68?(Tc), VO2 is insulator state, the transmission of infrared is very high. As the temperature goes above Tc, VO2 turns to metal state, with the transmission of infrared dropping abruptly. Currently, much attention was paid on the laser protection application of VO2.The main contents of this paper are as follow:1. The basic characteristics and the transition mechanism of VO2 has been briefly analyzed. Based on the effective medium theory(EMT), the properties of VO2-based nano-composite film was studied, which has formed the foundation of the following simulation and experiments.2. VO2 film with homogenous surface and 74% of infrared switching ratio was deposited on quartz substrate be magnetron sputtering.3. By using the software of TFCalc, the optical properties of VO2 film and VO2-SiO2 composite film at high temperature and low temperature have been simulated and analyzed. And the qualified Si/V ratio of VO2-SiO2 film for laser protection was determined, which guide direction for the experiments.4. The optical properties of VO2-SiO2 films fabricated with different RF power or Ar/O2 atmosphere by dual magnetron sputtering have been deeply discussed.5. With the silicon photocell protection experiment, the practicability of VO2 film for laser blind jamming protection was demonstrated. With the features of low transition threshold and high damage threshold, VO2 film was verified a promising material for laser protection.