J. Eur. Opt. Society-Rapid Publ. 21, 24( 2025) 241
Figure
10. The shortpass with QNL( blue) and the shortpass with Ta 2 O 5( red). The solid line shows the transmission, the dashed the reflection and the dotted the loss. Both designs have a total of 40 layers.
Figure
11. A double-side anti-reflective coating. The blue solid line indicates the transmission, the dashed the reflection and the dotted the absorption spectrum. The dotted red line shows the absorption spectrum of a Ta 2 O 5 single layer.
seen that it reaches a value of over 99 % at 266 nm. The dashed line represents the reflection, which is 0.2 % at 266 nm, and the dotted line represents the absorption. Based on the red dashed line, which shows the absorption of Ta 2 O 5, it can be observed that this antireflection coating is practically free of absorption at 266 nm, whereas Ta 2 O 5 would already absorb 70 % of the incoming light at this wavelength, making it unusable for this application.
4 Discussion
In this work, we were able to demonstrate that we are capable of producing QNL with high rates and very stable properties using the Clusterline 200 BPM coating tool from Evatec through a process we developed. We subsequently coated, measured, and evaluated a variety of these QNLs with different refractive indices and band gaps. TEM measurements allowed us to confirm the structure. We then used two different QNLs to coat two designs that we considered suitable. In both processes the layers were terminated using optical broadband monitoring. The first design represents a short pass system consisting of 40 layers. Since we also produced a comparable design using Ta 2 O 5, we were able to compare the two spectra. It is evident that, due to the lower absorption edge of the QNL, a larger transmission range exceeding 90 % is achieved compared to the Ta 2 O 5 design. The absorption of Ta 2 O 5 typically starts to grow significantly at the edge around 310 nm. With the chosen QNL mixture, this edge was successfully shifted by 20 nm into the shorter wavelength range. However, it can also be observed that, due to the mixing behavior of the