Inverse-source and inverse-diffraction problems in photonics

• Applicant: Professor Dr. Wolfgang Osten
• Subject Area: Optics, Quantum Optics and Physics of Atoms, Molecules and Plasmas
• Term: from 2011 to 2014
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 190815195

The proposed project concerns inverse scattering and inverse diffraction problems in photonics,i.e., problems of inferring the characteristics of either a light source (the inverse-sourceproblem) or scatterer (the inverse-diffraction problem) based on information provided by eitherthe measured properties of the scattered field or some a priori information. This type ofinverse scattering problems lie in the frontier area of diffractive optics, which have importantapplications such as the scatterometry for monitoring the critical dimensions of integratedcircuits. The proposed research will address challenges encountered in the development ofinverse-scattering theory and methodology in modern photonic applications. In particular, weconsider the inverse-diffraction problem of subwavelength surface-relief gratings and diffractiveoptical elements as well as the inverse-source problem of a wide class of partially coherentsources such as LEDs and Excimer lasers. Solutions to these inverse problems are essentiale.g. for non-invasive measurement of scattering surfaces and accurate modeling of partiallycoherent light combined with micro- and nano-optics. For solving both types of inverse problems,high-precision metrology systems are needed to perform accurate measurement of variousdiffraction quantities such as intensity, polarization, and coherence of light.

• DFG Programme: Research Grants
• International Connection: China, Finland
• Participating Persons: Professor Dr. Lifeng Li; Professor Dr. Jani Tervo; Professor Dr. Jari Turunen