Advanced optical interference filters based on metal and dielectric layers

Abstract

In this paper, we investigate the design and the fabrication of an advanced optical interference filter based on metal and dielectric layers. This filter respects the specifications of the 2016 OIC manufacturing problem contest. We study and present all the challenges and solutions that allowed achieving a low deviation between the fabricated prototype and the target.

Mechanical stress in dielectric mirrors: towards a fine control of the flatness

“…All the optical components were manufactured with the help of a HELIOS 4" machine, developed by Bühler/Leybold Optics, where low and high refractive index materials were both deposited through Plasma Assisted Reactive Magnetron Sputtering (PARMS) [4,5]. As seen in Fig.…”

New approaches for the design and the fabrication of pixelated filters

“…Such design technique allows obtaining a stack formula with any physically-valid spectral profile, usually with a lower total thickness that classical quarter-wave coatings which is an advantage for our purpose, but with arbitrary layer thicknesses which can add complexity for thickness monitoring during manufacturing. However, when associated with stable deposition processes, and efficient monitoring techniques, this design technique can lead to the manufacturing of complex filters with any profiles such as a landscapes [8] or a moose head [9] have been reported.…”

“…The filter is composed with 97 alternated high and low refractive index layers associated with a total thickness of 9.4 µm. While such a filter is far from being trivial to fabricate, it is however compatible with actual PARMS technology [9].…”

“…Since the design does not exhibit any periodicity and therefore tends to be very sensitive to deposition errors, we used a similar approach as the one we recently reported [9]. It is based on the decomposition of the design into substacks and the use of different monitoring glasses for each of these sub-stacks.…”

Trinary mappings: a tool for the determination of potential spectral paths for optical monitoring of optical interference filters

“…The choice of the optimal optical monitoring wavelength is therefore a critical step that will directly affect the final performances of the filter. Indeed, with some classical [4,6] or very complex filters [7], the error can quickly diverge and result in large discrepancies if the optical monitoring wavelengths are not properly selected.…”