Fiber confocal reflectance microscope (FCRM) for in-vivo imaging

In-vivo imaging can be achieved with a coherent-fiber-bundle based confocal reflectance microscope. Such a microscope could provide the means to detect pre-cancerous lesions in the cervix by characterizing cells' nuclear-to-cytoplasmic ratio. In this paper we present the design of such a fiber confocal reflectance microscope, with an emphasis on its optical sub-systems. The optical sub-systems consist of a commercially available microscope objective and custom designed telescope, scan lens, and coupling lens systems. The performance of the fiber confocal reflectance microscope was evaluated by imaging a resolution bar target and human cervical biopsy tissues. The results presented in this paper demonstrate a lateral resolution of 2 microm and axial resolution of 6 microm. The sensitivity of the system defined by the smallest refractive-index mismatch that can be detected is approximately Delta n 0.05.