University of New Mexico

The quest to visualize ever smaller biological structures has driven scientific progress. Spatial resolution and contrast, essential factors in imaging, are limited by the wavelength and the intensity noise, respectively. While shorter wavelengths (X-rays, electron beams) can improve resolution and fluorescent labeling can increase contrast, these benefits come at the expense of harmful radiation and invasive sample preparation. The project team proposes an optical instrument based on making differential measurements on the phase of two circulating ultrashort laser pulses in order to achieve unprecedented spatial resolution and sensitivity. The underlying physical principles, established in prior research programs at UNM, are the conversion of phase (or distance) as small as a billionth (10^-9) of a wavelength inside a laser to a measurable frequency and the discovery that the injection of even one trillionth (10^-12) of one pulse into the other is sufficient to change measurably the frequency of the latter. Equipped with mechanical nano-positioners, the complete instrument, which will be called the Scanning Phase Intracavity Nanoscope (SPIN), will provide three-dimensional images of biological objects with a spatial resolution of 1 nm. To be housed in the Cancer Research and Treatment Center Microscopy Facility, SPIN has the potential to serve the biomedical community by opening a new window to the intra-cellular nanoworld.