The objective of this project is to investigate several novel methods aimed at achieving the highest possible spatial resolution with a new instrument being developed for biological microscopy. The device is referred to as a Laser-Plasma Micro fluoroscope. It is, in essence, a miniaturized fluoroscope that uses low-energy x-rays to image individual cells and other thin specimens. Samples are placed in direct contact with a grainless fluorescent screen and illuminated with pulses of soft x-rays radiated by extremely hot laser produced plasma. The resulting unmagnified luminescent shadowgraph of the sample is viewed in real-time using light microscopy. The method produces images having extremely high depth-of-field, with three-dimensional information of overlapping features accessible using stereoscopic imaging methods. Key advantages of the instrument's design are its relatively low-cost, very compact size, and the ability to be used as an accessory device with standard light microscopes. In previous work, a very compact laser plasma source was constructed and used in conjunction with a light microscope to produce fluoroscopic images of cells at a spatial resolution near 200 nm. This project seeks to dramatically improve the resolution to a level routinely below 100 nm, and possibly below 50 nm for certain samples. Such unprecedented fluoroscopic resolution will require the development of innovative optical components. Phase I research will study the basic feasibility of two different approaches for achieving this resolution. Phase II will build upon these results to produce an advanced prototype instrument that will be appropriately designed for commercialization. With the significant improvement in resolution offered by this fluoroscopic technique over standard light microscopy, it should find widespread use in medical research, cell biology, microbiology, and other life sciences. It may also find applications in clinical medicine. Due to the ubiquitous nature of optical microscopy, the commercial potential of this work is very large.
