README: This document describes how to make use of the data used to produce the content of the manuscript, according to the open access regulations enforced by the funder(s). CREATOR: Douglas J. Paul (Douglas.Paul@glasgow.ac.uk) IDENTIFIER: TITLE: Ge-on-Si waveguides for sensing in the molecular fingerprint regime JOURNAL: Optics Express AUTHORS: UGNE GRISKEVICIUTE,1,2 ROSS W. MILLAR,1,2 KEVIN GALLACHER,1 JOAO VALENTE1 AND DOUGLAS J. PAUL1 1 University of Glasgow, James Watt School of Engineering, Rankine Building, Oakfield Avenue, Glasgow, G12 8LT, U.K. 2 These authors contributed equally to the work DATES: EPSRC project EP/N003225/1 started 1st July 2015, project end 30 June 2020, data released 14/2/20 SUBJECT: Associated data for figures shown in the manuscript. FUNDERS: This work was supported by EPSRC (EP/N003225/1) and Royal Academy of Engineering (RF/201819/18/187). RIGHTS: University of Glasgow METHODOLOGY: Fourier transform infrared spectroscopy measurements were taken using a Bruker Vertex 70 V system at room temperature, using a mid-infrared globar source and a DLATGS detector. Film absorption coefficients were calculated using the measured absorbance, and the film thickness as measured by ellipsometry. The absorbance calculation requires transmission measurements of bare Si wafers, and Si wafers coated with a thin film (PMMA or HSQ). Further description of the measurement is contained in the manuscript. Waveguide measurements were taken using a Daylight Solutions Mircat QCL laser package containing 4 separate QCL chips. The transmission of waveguides was carried out by stepping the laser in 10 or 20 nm increments (measurement dependent) and measuring the signal on a liquid nitrogen cooled detector. This is compared to waveguides coated with varying amounts of analyte (PMMA or HSQ). The laser was modulated with an optical chopper and a lock-in amplifier was used improve signal-to-noise ratios. DATA: The data is provided in tab delimited text files, with each file name corresponding to a figure in the manuscript. USE: Any use of the data is subject to a Creative Commons license (CC BY 4.0) and the Optics Express paper which first published the data should be cited.