Interest of broadband optical monitoring for thin-film filter manufacturing

Abstract

Broadband optical monitoring for thin-film filter manufacturing is more and more developed thanks to better performances of spectrometers with array detectors. We compare this optical monitoring with turning point monitoring and quartz monitoring of different designs. The sensitivity to thickness errors and to refractive index errors is evaluated. We show that real time determination of deposited thickness is a valuable criterion. We also present our experimental setup of transmittance and reflectance broadband optical monitoring. The use of a 400-1000 nm range combined with a signal-to-noise ratio of ϳ2500 in transmittance and 1000 in reflectance permits us to expect the manufacturing of high-performance non-quarter-wave designs. A first manufacturing of an 18-layer non-quarter-wave high-pass filter is provided.

Development of a real-time reflectance and transmittance monitoring system for the manufacturing of metaldielectric light absorbers

“…This monitoring system has been first tested through the manufacturing of beamsplitters and edge filters. As expected, the monitoring capabilities are improved compared to those of the previous system [8].…”

Practical optimization of a coating deposition process by application of hybrid monitoring strategies in an industrial production environment

“…A set of three hall sensors has been mounted close to the rotating substrate holder to generate trigger signals to initi ate spectrometer measurements when the substrate holder is in the relevant position. It has frequently been shown that broadband optical monitoring is extremely useful for highperformance coating deposition, when (environmentally) stable and reproducible optical film constants are guaranteed by the choice of a suitable deposition technique such as ion beam sputtering (IBS), magnetron sputtering (MS), ion plating, or (plasma) ionassisted electron beam evaporation ((P)IAD) [22,23]. Particularly, the suitability of the OptiMon system for monitoring PIAD processes using a Leybold APSpro plasma source [24] has frequently been demonstrated for PIAD processes at IOF.…”

Sensitivity of resonance properties of all-dielectric multilayers driven by statistical fluctuations

“…The component is then much more robust, which justifies the generalization of monochromatic optical control to all complex optical filters with narrow band (as presented here). On the contrary for the fabrication of broadband filters, a "Broadband" control is particularly well suited [60,61].…”