Photonic core fibers (PCFs) allow the formation of guided modes even in cores with refractive index lower than that of the cladding. A hollow core surrounded by the periodic structure can be filled up with different (gaseous or liquid) substances, which will alter the guiding properties (effective index of refraction, wavelength, photonic bandgap, attenuation, etc.) of the optical fibers in a measurable manner. Measuring one or many of these properties in the presence of biological samples allow the utilization of PCFs as sensitive optical biosensors or analyzers. Such sensors can also be realized using capillary tubes in which total internal reflection will assist the guided modes. Both approaches combine a small analytic volume and a high effective cross section for optical excitation referred to as optofluidics. The other advantage of the PCF structure is the wide range in which its dispersion and nonlinear properties can be varied so that an appropriate set of parameters allows the realization of collinear phase matching to produce quantum optical phenomenon that fits to all-fiber-optic systems. Based on the initial efforts within the NVKP_16-1-2016-0049 (AquaFluoSense) project, the applicant will join the 2017-1.2.1-NKP-2017-00001 (HunQuTech, Realization and sharing of qubits, and development of quantum information networks) and the recently started Quantum Informatics National Laboratory (QNL, 2020) projects.
Tasks: (1) Investigation of PCF and/or capillary based experimental systems to demonstrate fundamental quantum biology related phenomena (e.g. photosynthetic quantum efficiency and energy transfer) in plants using CW and picosecond scale laser excitations at room temperature (2) In case of low sample concentration, the detection sensitivity or selectivity can be increased by means of immunofluorescent techniques. In this procedure, an antigene–antibody chain is introduced in the analytic solution that selectively bonds to the molecule under test. Labeling the chain with a fluorophore gives information on the presence and concentration of the targeted substance selectively. Signal-to-noise ratio of the fluorescence probe to pump can be increased by advance detection techniques that are also to be investigated. (3) Investigation of the dispersion and nonlinear properties of PCFs to demonstrate a twin-photon source based on collinear phase matching. Some elements of this proposal may reach beyond the frameworks of the related projects, so their weight may vary according to the advances in the proposed work and the projects.
Fluent English required. Good abstraction and math skills, fundamental knowledge of optics, optoelectronics and laser physics, interdisciplinary and experimental approach as well as high degree of self-support are preferred. Fundamental optical design skills (e.g. in Zemax environment) are advantageous.