Toward a Compact Dual-Wedge Point-Scanning Confocal Reflectance Microscope

摘要

Confocal reflectance microscopy has been shown to provide optical sectioning and resolution sufficient to provide useful information about cellular structure in vivo. However, existing instruments are large and expensive, because of the need for fast, two-dimensional scanning in the pupil, and the associated relay optics. A more compact scanning system could lead to an affordable handheld instrument for in vivo imaging. Several approaches are being considered to minimize instrument size with different advantages and disadvantages. Here we report one approach that incorporates a dual-wedge scanner within a point-scanning configuration. The dual-wedge scanner could reduce the cost and complexity of the confocal reflectance microscope while retaining the resolution and optical sectioning abilities of current point-scanning instruments. The scanner is implemented by replacing the scanning mirrors and the relay telescope between them with two optical prisms that are rotated about the optical axis. This scanning configuration produces a spiral scan if the prisms are rotated in the same direction, or a rosette scan if the prisms are rotated in opposite directions. Preliminary experimental results with the microscope show a lateral resolution on the order of 1 - 2 micrometers and on-axis optical sectioning on the order of 3 - 4 micrometers.