This project is funded by the National Science Foundation (NSF) through award DBI-0500812 for Biological Sciences Instrument Development. Tip fabrication was assisted through NSF support (ECCS-NSF-0520891).
We present the development of a versatile spectroscopic imaging tool to allow for imaging with single-molecule sensitivity and high spatial resolution. The microscope allows for near-field and subdiffraction-limited far-field imaging by integrating a shear-force microscope on top of a custom inverted microscope design. The instrument has the ability to image in ambient conditions with optical resolutions on the order of tens of nanometers in the near field. A single low-cost computer controls the microscope with a field programmable gate array data acquisition card. High spatial resolution imaging is achieved with an inexpensive CW multiphoton excitation source, using an apertureless probe and simplified optical pathways. The high-resolution, combined with high collection efficiency and single-molecule sensitive optical capabilities of the microscope, are demonstrated with a low-cost CW laser source as well as a mode-locked laser source.
Nowak, D., Lawrence, A., & Sánchez, E. (2010). Apertureless near-field/far-field CW two-photon microscope for biological and material imaging and spectroscopic applications. Applied Optics, 49(35), 6766-6771.