THz Sensor Compensation Structure for Multiple Reflection Suppression

The patent applies anti-reflection coatings on the lens surfaces to convert the harmful reflective effect into a beneficial transmission effect. By manipulating the refractive index and thickness of coating layers, the reflected beams are converted into transmitted beams, eliminating multiple reflections while maintaining the focusing capability of the lens. This resolves the contradiction by preserving the measurement accuracy improvement from lens focusing while eliminating the harmful multiple reflections from lens surfaces.

The patent introduces an anti-reflection coating as an intermediary layer between the lens material and the surrounding medium. This intermediate layer with optimized refractive index reduces the impedance mismatch at the interface, thereby minimizing reflections. The coating acts as a mediator that allows the lens to maintain its focusing function while suppressing the generation of harmful reflected beams that would otherwise compromise measurement accuracy.

By applying anti-reflection coatings with optimized refractive indices and thicknesses, the patent converts the harmful reflective effect that increases with lens surface area into a beneficial transmission effect. The coating layers are designed to minimize reflections across the entire lens surface, allowing the lens to achieve improved focusing quality through increased surface area without proportionally increasing the amount of harmful reflected radiation.

The patent changes the optical parameters of the lens system by introducing coating layers with specific refractive indices and thicknesses. This parameter modification allows the lens to maintain or improve focusing quality while suppressing reflections. The refractive index gradient created by the coating layers reduces the abrupt impedance change at the lens surface, thereby minimizing reflections even as the lens surface area increases for better focusing.