1. DLC in optics Student talk SaaraHirvonen 5.12.2013

2. Contents Introduction DLC opticalproperties Optical applications Futuretrends Summary Saara Hirvonen

3. Introduction Typical DLC applications: wear resistance DLC films have amorphous structure • Properties can be adjusted Optical coatings are essential in advanced applications • Filtering of specific wavelengths • Reflection and deflection • Reflection reduction Saara Hirvonen

4. DLC opticalproperties Reflectiveindex 2.0 • Goodbroadbandgapanti-reflection (BBAR) performance Optical transparencyNIR-FIR Layerthicknessoptimized for specificwavelength1,2 1) A. Grill. 1999. 2) Tydex. Saara Hirvonen

5. Optical applications • Military and marine windows • Outdoor thermal cameras 4 3 IR opticalsystemscoating with DLC • Anti-reflection • Resistance to abrasion, salts, acids, alkalis and oil 2,3 2) Tydex. 3)Jenoptik. 4) Reynard Corporation. Saara Hirvonen

6. Optical applications: IR antireflectioncoating Substratematerials • Ge, Si • ZnS, ZnSe, glass, ceramics, crystals, plastics4 Spectralrangedepending on coatingthickness • Wavelengths 3-5 µm and 8-12 µm Deposition with PECVD • Standard process for Ge and Sisubstrates5 4) Reynard Corporation. 5) LeyboltOptics. Saara Hirvonen

7. Futuretrends– Coatingimprovement DLC single-layer coating • Stable structure • Spectral performance is limited at specific wavelength • Averagereflectance 2,6 % for long-wavelength IR spectralrange Hybrid-DLC • Antireflectionpropertiesimproved with differentlayers • Reflectance of <0.15% • Multilayer coating enables broader working bandwidth 6,7 6) M. Degel & E. Gittler. 2013. 7) M. Gilo. 2013. Saara Hirvonen

8. Coatingimprovement: hybrid-DLC 7 1- 50 dielectric layers with PVD DLC with PECVD Fewer optical components needed Saara Hirvonen

9. Summary DLC opticalproperties • Good BBAR performance • Optical transparency NIR-FIR IR opticalsystemscoating • Anti-reflection • Environment resistance Hybrid-DLC • Multilayer coating enables broader working bandwidth Saara Hirvonen

10. Thank you! Questions?

11. References Properties 1) A. Grill. Electrical and optical properties of diamond-like carbon. Thin Solid Films. Vol:355-356. 1999. http://carbon.utsi.edu/downloads/AGrill_electrical_optical_dlc.pdf 2) Tydex. Hard Carbon Coating (DLC: "Diamond-Like Coating") http://www.tydexoptics.com/materials1/coatings/dlccoatings/ IR coatings 3)Jenoptik. Diamond-Like-Carbon (DLC) Coatings. http://www.jenoptik.com/en-diamond-like-carbon-coatings 4) ReynardCorporation. DiamondLikeCoatings – ClearDLC. http://www.reynardcorp.com/cleardlc.html 5) Leybolt Optics. DLCcs - Diamond Like Carbon Coating System. http://www.leyboldoptics.com/optics/precision-optics/machines/dlccs/dlccs.html Hybrid DLC 6) Michael Degel& Elvira Gittler. Multispectral Optical Coatings Are Tough, Versatile for IR Applications.Jenoptik Optical Systems GmbH. 2013. http://www.photonics.com/Article.aspx?AID=53225 7) MordechaiGilo. Low-reflectance, durable coatings for infrared lenses. SPIE Newsroom. 2013. DOI: 10.1117/2.1201212.004581http://spie.org/x91883.xml