===== Particles Trapped =====

=== What others have Trapped ===
  -gold (2 to 5 μm in diameter): almost spherical
  -silver (2 or 3 μm): irregularly shaped
  -bronze (2 to 15 μm): almost spherical
    * Shunichi, S., Yasunori H., and Yoshio W., "Optical trapping of microscopic metal particles," //Opt. Lett.// **19**, 1807-1809 (1994).
  -silicon particles of 5-20 µm; nonspherical particles trapped better
    * Zhang, Z., Cannan, D., Liu, J., Zhang, P., Christodoulides, D. N., Chen, Z., "Observation of trapping and transporting airborne absorbing particles with a single optical beam." //Optics Express.// **20**,  16212-16217 (2012).
  -graphite particles: 5 microns, 25-30mW
  -carbon nanoparticles: 1-5mW
    * Shvedov, V., Hnatovsky, C., Rode, A. V. & Krolikowski, W., "Robust trapping and manipulation of airborne particles with a bottle beam". //Optics Express// **19**, 17350-17356 (2011).
  -graphite coated glass shells between 50 and 100 microns
    * Eckerskorn, N. O., Zeng, N., Shvedov, V., Krolikowski, W. & Rode A. V., "Effect of polarization on transport of particles in air by optical vortex beam". //Journal of Optics// **14**, 1-5 (2012)
  -grass smut spores
  -tryptophan
    * Pan, Y., Wang, C., Hill, A. C., Coleman, M., Beresnev, L. A. & Santarpia, J. L. "Trapping of individual airborne absorbing particles using a counterflow nozzle and photophoretic trap for continuous sampling and analysis". //Applied Physics Letters.// **104**, 1-4 (2014)
  -gold-coated hollow glass spheres (300 nm diameter)
    * Shvedov, V., Davoyan, A. R., Hnatovsky, C., Engheta N. & Krolikowski W., "A long-range polarization-controlled optical tractor beam". //Nature Photon.// **8**, 846-850 (2014).


=== What we have Trapped===
  -black liquor → also puffing
  -nano-diamonds (~100nm) → only nebulized
  -graphite (44 micron; 325 mesh)
  -tungsten (1-12 micron; mostly 4-6)
  -printer toner (powder)
  -dried sharpie ink 
  -rhodamine-g (powder)
  -salt
  -glass beads (10-30 micron)
  -iron filings
  -silver powder (4-7 microns)

=== What didn't trap ===
  -aluminum powder (17-30 micron)
  -magnesium oxide (45 microns)
  -dry polystyrene
  -silver powder (1.3-3.2 microns)

=== What we want to trap ===  
{{itsatrap.jpg}}
  -nano-tungsten
  -aqeous polystyrene