Separation of optical thin film and substrate absorption by obliquely-crossed photothermal deflection: Theory

摘要

An explicit three-dimensional calculation of c.w. modulated phofolherrmd deflection (PTD) with obliquely crossed geometry, including uptictd thin film and subHtrnte absorption, has been presented. Theoretical results show thiit the obliquely crossed PTD technique is feasible to separate the thin film and HubflEnite absorption, and to measure low thin film absorption under high substrate absorption by appropriately adjusting the cross-point position of the excitation and probe beams. Measurement of the thin film absorption is not affected by the thermal properties of the substrate, The obliquely crossed PTD ilsii provide. method for reul-time monitoring of thin film generation.