Fabrication of a fiber scanning multiphoton microendoscope

• Online Access: http://hdl.handle.net/2047/D20328713

Microendoscopy is a technique that involves imaging deep within the body including small volume locations. These devices are essentially miniature microscopes for linear (confocal or wide-field) or nonlinear (multiphoton) imaging applications. The multiphoton excitation technique provides a method to generate nonlinear modes of tissue contrast, including autofluorescence using non-linear near infrared excitation, harmonic generation and long wavelength (~1000 to 1700 nm) generation of visible fluorescence from exogenous probes. This thesis introduces simple methods to fabricate a stable low-cost fiber scanning microendoscope probe that facilitates miniature laser scanning multiphoton microscopy. We introduce enhancements that ease fabrication and improve performance including: (1) the use of 3D printed parts to construct the fiber scanner in place of expensive and labor intensive ceramic parts(in combination with a miniature piezoelectric tube); (2) video rate scan speeds using higher modes of fiber resonance; (3) custom design of an achromatic microlens objective to achieve diffraction limited resolution over a field of view of several hundred microns. We anticipate that these developments will enhance the applicability of fiber scanning multiphoton microendoscopy for in vivo imaging of preclinical models as well as the potential for clinical translation to image human disease.