Real Time Fiber Optic Endoscopy Devices.

摘要

Optical fibers are mostly used to transfer images or spectral information for endoscopic probes in biomedical applications. In addition to the transmission task, their optical properties are utilized to make them more functional. For example, group velocity dispersion occurring in the fibers separates the wavelengths of the light in time domain; and hence put the wavelength information serial in time of the output. If these serial wavelengths in time domain are sent to different directions by an optical component, the capability of encoding wavelengths both in time and space is obtained. This dual encoding of wavelengths which is the focus of this thesis is a powerful technique for optical fiber based spectroscopic and endoscopic applications. Since each wavelength of the light picks up the information from the different parts of the sample surface at different times, the topographic changes or features of the surface can be directly detected from the spectral or time analyses. By doing so, surfaces and dynamics can be measured in real time with the proposed fiber optic probe.;The resolution of the real time endoscopic fiber optic probe is limited by the components used in the probe, the optical pulses, and the digital oscilloscope. Crosstalk between wavelength channels and collecting information of different spatial points of the sample at one wavelength channel degrades the resolution. Pulse repetition rate and temporal duration of the pulse determine the temporal crosstalk which occurs as two adjacent pulses overlap. This thesis focuses on analyses of spatial and detection resolution; interchannel, intrachannel, and temporal crosstalk.