Absorbance-Based Integrated Optical Sensors -- Luminescence Lifetime-Based Imaging of Sensor Arrays for High-Throughput Screening Applications -- Cataluminescence-Based Gas Sensors -- Hollow Waveguide Infrared Spectroscopy and Sensing -- Combinatorial Method for Surface-Confined Sensor Design and Fabrication -- The Interplay of Indicator, Support and Analyte in Optical Sensor Layers -- Challeng…