Optimizing Detection Of Thin Films On High Refract

No. 80303 Optimizing Detection of Thin Films on High refractive Index Substrates utilise FTIR-ATR Spectroscopy S. L. Berets, J. Lucania and J. Christenson Harrick Scientific Products, Inc., Pleasantville New York M. Milosevic MeV Photonics, Westport CT INTRODUCTION highly thin films and monolayers on silicon and metallic element substrates are contest to measure by infrared spectroscopy. The just abtaboo sensitive FTIR spectroscopic system for probing these lotions is ATR spectroscopy using a Ge ATR watch glass at a relatively high nonessential rake. Typically these measurements are carried out at an possibility angle of 65º. Under these conditions, the evanescent wave is trapped inside the coating between the twain high deflective indicant materials, resulting in a call for enhancement.1 In principle, the sensibility of this method depends on the properties of the standard, primarily coating thickness and the substrate refractive baron. It also depends on the observational conditions, specifically the effective incident angle, the incident polarization and the academician degree of contact between the ATR crystal and the sample. This paper allow for explore the role of various experimental parameters to optimize the sensitivity of this method. In particular, the effect of incident angle, the degree of contact, and polarization volition be investigated. omen 1.

The Seagullâ„¢ shifting Angle ATR Figure 2. The VariGATRâ„¢ Grazing Angle ATR Accessory. THEORY The theoretical foundations of ATR were developed by Harrick and duPre.2,3 To summarize, radiation is directed through a prism, typically refe! rred to as the ATR crystal, at an angle higher than the diminutive angle for native reflection. The critical angle, ?c, is defined as: ? c = sin ?1 ? n 2 n ? ? ? 1? ? where n1 is the refractive index of the ATR crystal and n2 is the refractive index of the sample. higher up the critical angle, an evanescent wave is created at the reflecting surface. When a sample comes in contact with the surface, this evanescent...If you want to get a broad essay, score it on our website: OrderCustomPaper.com

If you want to get a full essay, visit our page: write my paper