High-Speed Near-Field Scanning Optical Microscopes with Enhanced Capabilities for Nanoscale Optical Measurements and Interactions based on Ultra-High-Power Sub-Wavelength Probe

Statement of the Problem or Situation that is Being Addressed Near-field scanning optical microscope (NSOM) offers the use of a nano-dimension light energy source with a diameter much smaller than the wavelength of light to achieve resolutions significantly (around 10 times) better than the usual optical microscope. NSOM has found wide usages and become an important measurement instrument for nano-technologies, nano-manufacturing, optical technologies, bio-technologies, and nanocale science and engineering experimentations. However, the current NSOM probes can only provide nano-Watts optical output power which severely limits the applications of NSOM. This is because current technology uses very lossy metal-coated tip to produce the small light source. Statement of How this Problem or Situation is Being Addressed The proposed technology in this DOE proposal based on a new approach involving a nano-wavguide technology will enable much higher optical output power from NSOM probes that is 100 to 10,000 times higher than current probes with nanoscale spot size of down to about one tenth of the wavelength of light. The phase I technical objective is to develop a proof-ofconcept prototype for the proposed ultra-high-power NSOM probe tips that can provide power output of 10 micro-Watts to 0.1 milli-Watts, instead of nano-Watts of current probes. A prototype NSOM instrument utilizing the probes will also be developed. The prototype instrument will be demonstrated at 1550nm wavelength range. In Phase II, the approaches will be expanded to develop a full series of ultra-high-power NSOM probes and NSOM instruments covering a wide wavelength range from visible to infrared with substantial performance advantages over current technologies. Commercial Applications and Other Benefits If this SBIR is funded by DOE, the new type of NSOM probes with ultra-high brightness will enable the use of NSOM for many other applications not currently possible. For example, higher power will enable higher scanning speed or larger scanning area. It will also enable application to high-spatial-resolution molecular spectroscopy or Raman spectroscopy. Attempts have already been made in the physics and chemistry community to use NSOM for specialized lithography. In the biological or nanotechnology community, high-power NSOM probes could be used to stimulate localized chemical material synthesis, or apply physical pressures and forces to cut samples with nanoscale precision. These will be very important for enabling future studies in nano-technolology, nano-manufacturing, nano-medicine, nano-chemistry, and nano-biology. There are thus potentially many new market segments in nanotechnologies NSOMs could address if higher optical output powers are possible. Key Words Nanotechnology, Advanced Materials and Manufacturing, Instrumentation for Nanotechnology, Near-Field Scanning Optical Microscope, Laser, Detector, Near-Field Imaging, Nano-photonics. Summary for Members of Congress Near-field scanning optical microscope (NSOM) uses a nano-dimension light energy source for imaging and is widely used in nanotechnology. Current NSOM can only provide nano-Watts optical scanning power. The proposed technology enables NSOM probes that is 100 to 10,000 times brighter, which will enable many nanotechnology applications not currently possible.