Sapphire plates, regarded as high-performance optical components, have been extensively utilized in laser systems, semiconductor equipment and other domains. This is attributable to their exceptional physical and chemical properties. The customized specifications and coating configuration of sapphire plates are directly related to the effect of terminal applications; as such, it is necessary to carry out refined design according to specific requirements.

In the context of customizing specifications, the core parameters of sapphire plates include key indicators, such as geometric dimensions, thickness tolerance and surface accuracy. In the context of special application scenarios, such as sapphire plates utilized in industrial inspection equipment, it is compatible with customization not standardized in size, with a maximum diameter of 150 mm.

The selection of thickness necessitates a comprehensive consideration of the balance between light transmittance and mechanical properties. A sapphire plate with a thickness of 1mm exhibits a light transmittance of over 85% within the wavelength range of 400-5000nm. However, an increase in thickness to 3mm results in a 30% enhancement in mechanical strength, accompanied by a reduction in light transmittance within the short-wave range of approximately 5%. In ultraviolet laser applications, sapphire plates with a thin design of 0.5 to 1mm are typically used. In observation window of the vacuum chamber, the utilization of sapphire plates with a thickness ranging from 3 to 5 mm is recommended to ensure optimal sealing performance.

In relation to the configuration of coatings, the implementation of functional optical coatings has the potential to substantially extend the application scope of sapphire plates. Anti-reflective coatings are a common configuration. A single-layer coating of MgF2 has been shown to reduce reflectivity within the wavelength range of 350-700nm to below 1.5%. In contrast, a broadband multi-layer AR coating has been demonstrated to achieve an average reflectivity of less than 0.5% in the 400-2000nm range.

The utilization of high-power lasers in a variety of applications imposes stringent requirements on the coatings applied. The lifespan of conventional AR coatings when subjected to continuous laser irradiation at a rate of 10kW/cm² is typically limited to 500 hours. The laser-resistant coating, which has been designed with a gradient refractive index, has been shown to be capable of increasing the damage threshold to 25J/cm² (1064nm, 10ns pulse) by alternately depositing ultra-thin layers of HfO2 and SiO2.

The implementation of customized production processes necessitates rigorous quality control measures. The selection of raw materials is of paramount importance, and therefore C-direction sapphire crystals grown by the EFG method should be adopted to ensure that the birefringence is less than 5×10^-6. In the fine processing stage of the manufacturing process, numerical control ion beam polishing is used to ensure surface shape accuracy is maintained within the specified range of 0.1 μm. The coating process necessitates real-time monitoring of the film thickness, with an error limit of ±1% of the designed value. The finished products are required to pass a full inspection, which includes 12 indicators such as interferometer detection of surface shape, spectrophotometer testing of transmittance, and laser damage threshold testing.

The differentiation of application scenarios gives rise to the development of special models of sapphire glass. The window of the vehicle-mounted lidar must be engineered to be shockproof, with the capacity to withstand a mechanical shock of 20G. Ultra-high purity sapphire glass for semiconductor equipment, characterized by stringent control of metal impurity content at the ppb level. The integration of the temperature control window of the heater enables stable operation within a range of -100° to 350°C.

In the process of selecting sapphire plates, three major elements must be given full consideration. The initial consideration is that of the optical performance parameters, incorporating such factors as the operating wavelength, transmittance requirements, and wavefront distortion tolerance. The second consideration is mechanical environmental parameters, involving pressure differences, vibration conditions, temperature cycling ranges, etc. The third factor pertains to chemical environmental factors, encompassing exposure to acids and bases, as well as contact with organic solvents.

The advent of technological advancement has precipitated two significant innovative trends in the domain of sapphire plates. Firstly, there has been a notable progression in the field of composite functionalization, exemplified by the integration of sapphire with silicon plates to create multispectral windows, or the incorporation of microstructures for the fabrication of diffractive optical elements. Secondly, there has been a marked emphasis on intelligent upgrades, characterized by the embedding of optical fibre sensors to facilitate real-time stress and strain monitoring. These innovations have resulted in the expansion of the application boundaries of traditional sapphire plates, thus enabling them to evolve from passive optical components into an integral component of intelligent systems.