Efficiency of integrated waveguide probes in the detection of fluorescence and backscattered light

摘要: Integrated optical probes for detecting backscattered light in, e.g., Raman spectroscopy show desirable characteristics compared to conventional fiber probes, although the latter ones may have better collection efficiency in many cases. Major advantages of integrated include reduced size; background noise due scattering probe because propagation length; potential monolithic integration with filters and spectrometers; very small volume, providing high spatial resolution; polarization maintenance. We demonstrate that when scattered needs be collected from a thin layer close surface, can than do. modeled multimode waveguide by adapting an analytical model had been developed probes. The was extended order account arbitrary geometries low number discrete modes quasi-continuum typical fiber. Using this we efficiencies sample. found has higher thickness probe-to-layer distance both smaller ~100 um.