Zhou, XuewenSpectroscopy plays a crucial role in biological measurements by offering functional insights across various biological scales, from cellular to organ levels. It has become an important complement to imaging technologies. The thesis focuses on enhancing spectroscopy-based methods, addressing both technical advancements and application-oriented improvements. The first part of the research presents the development of standardized test methods for multispectral photoacoustic imaging (MPAI), a phantom-based test method specific for evaluating MPAI performance in breast cancer detection. This test method contributes to standardizing the evaluation of multispectral photoacoustic imaging across different research and clinical settings with better reliability and reproducibility. The next segment of the thesis introduces an innovative 2D-dispersion spectrometer, utilizing an etalon and grating setup. This instrument significantly improves the sensitivity in detecting Whispering Gallery Mode (WGM) microlasers by providing spectral resolution less than 0.3 pm. The enhanced sensitivity allows for the measurement of hyperfine refractive index and absorption changes in liquid environments, which expands the application limit of microlasers as biosensors. In the final part, the thesis extends the application of the 2D-dispersion spectrometer to detect Brillouin and low-frequency Raman signals. For the best of our knowledge, this is the first setup demonstrating simultaneous Brillouin and low-frequency Raman measurement, which can provide mechanical and chemical information of a sample such as the viscoelasticity and intermolecular dynamic.enDissertationBiomedical engineeringgratinglow-frequency Ramanmicrolaserphotoacoustic imagingspectroscopyVIPA