Complex optical interference filter with stress compensation
Abstract
We present hereafter the results on the fabrication of complex optical filters within the Institut Fresnel in close collaboration with CILAS. Bandpass optical interference filters, with central wavelengths ranging in near ultraviolet or in the near infrared, were deposited on both sides of glass substrates with a very good congruence with theoretical designs. For these applications, the required functions are particularly complex as they must present a very narrow bandwidth as well as a high level of rejection over a broad spectral range. Moreover, in order to satisfy more and more critical specifications on flatness of the component treated on both faces, the stress induced by the different layers has to be taken in account in the filter design. All these components were manufactured using Plasma Assisted Reactive Magnetron Sputtering (PARMS) technics offered by the HELIOS machine and monitored in real time with an OMS5000 in-situ optical monitoring, both developed by BUHLER Optics. Compressive mechanical stress of 364 MPa and 55 MPa respectively for SiO2 and Nb2O5 are measured, final sag of 326 nm and 13 nm, and uniformity from -0.05% to 0.10% and from -0.10% to 0.20% are obtained respectively for the two manufactured filters.
- Publication:
-
Society of Photo-Optical Instrumentation Engineers (SPIE) Conference Series
- Pub Date:
- September 2015
- DOI:
- 10.1117/12.2191967
- Bibcode:
- 2015SPIE.9627E..0RB