Competitive light beam splitters based on complex interference wedged structures that use low-reflectivity components (Fresnel reflection)

Abstract

We demonstrate that interference wedge structures suitably composed of wedged purely glass elements using Fresnel reflection only can be effectively employed for realization of competitive light beam splitters and filters (especially for high-power laser beams). The theoretical analysis, simulation and experimental testing show that for appropriately chosen parameters and for a suitably composed interference complex such structures can achieve a controlled variable transmission in a wide range (99% – ∼30%) and reflection from ∼2% to ∼70%. The traditional realization of purely glass splitters ensures no more than ∼20% reflectivity. The splitters proposed are very compact sheet-like elements (e.g., 5×3×0.2 cm) and the splitting is implemented by sliding in the splitter’s plane. Thus, the propagation direction of the formed beams is preserved. The incident beam on the purely glass splitter (no dielectric or metallic mirrors) can be of high power and the influence of the air humidity is strongly reduced; also, cleaning the filter surfaces presents no difficulties. A single splitter can work in a wide range of wavelengths (IR, visible) without polarization dependence for incident angles up to ∼20°.