MULTIPHOTON SPECTROSCOPY THROUGH OPTICAL SINGLE MODE FIBERS

组织中的自体荧光可用作诊断工具， 光动力疗法（例如用于癌症）。 多光子激发;即 近红外波长范围;可用于自体荧光 在生物组织最透明的地方成像。 但 穿透深度仍然有限（~200？m）甚至更有问题 用于自体荧光检测。 使用单模光纤 同时激发和检测（多光子内窥镜）提供了 一个很好的解决方案。 因此，初步研究 飞秒激光脉冲（810-980 nm）的展宽效应以及 研究了光纤耦合效率与光强的关系 出去 此外，检测到的荧光（荧光素，~200？M; 溶解在水中）通过相同的纤维已经解决了在 频域 功率相关测量揭示了一个真正的 双光子荧光

Autofluorescence in tissues can be used as a diagnostic tool in photodynamic therapy (e.g. for cancer). Multiphoton excitation; i.e. near infrared wavelength range; can be used for autofluorescence imaging where biological tissues are most transparent. However, the penetration depth is still limited (~200 ?m) and even more problematic for autofluorescence detection. Using single-mode fiber for both excitation and detection simultaneously (mutliphoton endoscopy) offers an excellent solution. Therefore, preliminary studies on the broadening effects of femtosecond laser pulses (810-980 nm) and the intensity-dependence of the fiber coupling efficiency has been carried out. Furthermore, the detected fluorescence (of fluorescein, ~200 ?M; dissolved in water) through the same fiber has been resolved in the frequency domain. Power-dependent measurements reveal a genuine two-photon fluorescence.