General relation for group delay and the relevance of group delay for refractometric sensing Hoekstra, Hugo J. W. M. Hammer, Manfred tet_topic_waveguide ddc:530 The relevance of our definition for sensitivity in refractometric sensing, being the relative change in the transmittance of a certain output channel of an optical device over the change in the refractive index of the probed material, is discussed. It is compared to one based on spectral shift per refractive index unit change. Further, there is discussion on how group delay and sensitivity are interrelated and can be converted into each other and which physical quantities are relevant for high sensitivity. As a by-product of the theory presented, a general expression relating group delay and the ratio of the time-averaged optical energy and the input power is presented. The Optical Society 2014 info:eu-repo/semantics/article doc-type:article text http://purl.org/coar/resource_type/c_6501 https://ris.uni-paderborn.de/record/3937 Hoekstra HJWM, Hammer M. General relation for group delay and the relevance of group delay for refractometric sensing. <i>Journal of the Optical Society of America B</i>. 2014;31(7). doi:<a href="https://doi.org/10.1364/josab.31.001561">10.1364/josab.31.001561</a> eng info:eu-repo/semantics/altIdentifier/doi/10.1364/josab.31.001561 info:eu-repo/semantics/altIdentifier/issn/0740-3224 info:eu-repo/semantics/altIdentifier/issn/1520-8540 info:eu-repo/semantics/closedAccess