Here we describe a simple optical design for a MEMS-based dual-axes fiber optic confocal scanning microscope that has been miniaturized for handheld imaging of tissues, and which is capable of being further scaled to smaller dimensions for endoscope compatibility while preserving its field-of-view (FOV), working distance, and resolution. Based on the principle of parallel beams that are focused by a single parabolic mirror to a common point, the design allows the use of replicated optical components mounted and aligned within a rugged cylindrical housing that is designed for use as a handheld tissue microscope. A MEMS scanner is used for high speed scanning in the X-Y plane below the tissue surface. An additional design feature is a mechanism for controlling a variable working distance, thus producing a scan in the Z direction and allowing capture of 3-D volumetric images of tissue. The design parameters that affect the resolution, FOV, and working distance are analyzed using ASAP^TM optical modeling software and verified by experimental results. Other features of this design include use of a solid immersion lens (SIL), which enhances both resolution and FOV, and also provides index matching between the optics and the tissue.

Date Published: 14 February 2007
PDF: 9 pages
Proc. SPIE 6443, Three-Dimensional and Multidimensional Microscopy: Image Acquisition and Processing XIV, 64430E (14 February 2007); doi: 10.1117/12.699484

Published in SPIE Proceedings Vol. 6443:
Three-Dimensional and Multidimensional Microscopy: Image Acquisition and Processing XIV
Jose-Angel Conchello; Carol J. Cogswell; Tony Wilson, Editor(s)