Complex refractive index variation in proton-damaged diamond

• Published in: Optics express Vol. 20; no. 17; pp. 19382 - 19394
• Main Authors: Lagomarsino, S, Olivero, P, Calusi, S, Monticone, D Gatto, Giuntini, L, Massi, M, Sciortino, S, Sytchkova, A, Sordini, A, Vannoni, M
• Format: Journal Article
• Language: English
• Published: United States 13.08.2012
• Subjects: Computer Simulation; Diamond - chemistry; Diamond - radiation effects; Light; Models, Chemical; Protons; Refractometry - methods; Scattering, Radiation
• ISSN: 1094-4087
• DOI: 10.1364/OE.20.019382

An accurate control of the optical properties of single crystal diamond during microfabrication processes such as ion implantation plays a crucial role in the engineering of integrated photonic devices. In this work we present a systematic study of the variation of both real and imaginary parts of the refractive index of single crystal diamond, when damaged with 2 and 3 MeV protons at low-medium fluences (range: 10(15) - 10(17) cm(-2)). After implanting in 125 × 125 μm(2) areas with a scanning ion microbeam, the variation of optical pathlength of the implanted regions was measured with laser interferometric microscopy, while their optical transmission was studied using a spectrometric set-up with micrometric spatial resolution. On the basis of a model taking into account the strongly non-uniform damage profile in the bulk sample, the variation of the complex refractive index as a function of damage density was evaluated.