*Daniel Gloess¹, Andy Drescher¹, Ullrich Hartung¹, Manuela Junghähnel¹, Peter Frach¹, Martin Ebert², Hagen Sahm^3
1Fraunhofer Institute for Organic Electronics, Electron Beam and Plasma Technology FEP, Dresden, Germany; ²Laseroptik GmbH, Garbsen, Germany; ³SeeReal Technologies GmbH, Dresden, Germany
The PreSensLine inline coating system at Fraunhofer FEP is ideally suited for the high-precision coating of substrates up to 650 x 750 mm² with thicknesses up to 120 mm. In this paper, investigations on the deposition of multilayer coatings for future laser applications are presented. One example is an investigation on large laser mirrors for high-power laser systems. The layer system of Ta₂O₅ and SiO₂ in (HL)14H design (29 layers) was optimized for R>99.8% (unpolarized) at 803 nm and 45° incidence angle. The samples were analyzed regarding optical function, absorption, scattering, hardness, mechanical stress, roughness, particle density, and laser-induced damage threshold (LIDT). In particular, very low absorption and low mechanical stresses demonstrate the suitability of the process for coating future highly demanding laser components. Further investigations are on layer systems needed for backlights of holographic displays using three color laser illumination. By applying laterally graded precision optical filters with dimensions of the display size, very compact backlight designs are feasible.