Doped Nanocrystalline Diamond Films as Reflective Layers for Fiber-Optic Sensors of Refractive Index of Liquids

• Published in: Materials Vol. 12; no. 13; p. 2124
• Main Authors: Kosowska, Monika, Majchrowicz, Daria, Sankaran, Kamatchi J, Ficek, Mateusz, Haenen, Ken, Szczerska, Małgorzata
• Format: Journal Article
• Language: English
• Published: Switzerland MDPI AG 02-07-2019; MDPI
• Subjects: Aluminum; Boron; boron-doping; Chemical vapor deposition; Data analysis; Diamond films; doped nanocrystalline diamond films; Experiments; Fiber optics; fiber-optic; Liquids; Microwave plasmas; Nanocrystals; Nitrogen; nitrogen-doping; optical fiber sensor; Optical properties; Optics; Plasma enhanced chemical vapor deposition; refractive index sensor; Refractivity; Sensors; Silicon; Silicon substrates; Japan; doped nanocrystalline diamond films; boron-doping; fiber-optic; optical fiber sensor; nitrogen-doping; refractive index sensor
• ISSN: 1996-1944; 1996-1944
• DOI: 10.3390/ma12132124

This paper reports the application of doped nanocrystalline diamond (NCD) films-nitrogen-doped NCD and boron-doped NCD-as reflective surfaces in an interferometric sensor of refractive index dedicated to the measurements of liquids. The sensor is constructed as a Fabry-Pérot interferometer, working in the reflective mode. The diamond films were deposited on silicon substrates by a microwave plasma enhanced chemical vapor deposition system. The measurements of refractive indices of liquids were carried out in the range of 1.3 to 1.6. The results of initial investigations show that doped NCD films can be successfully used in fiber-optic sensors of refractive index providing linear work characteristics. Their application can prolong the lifespan of the measurement head and open the way to measure biomedical samples and aggressive chemicals.