A new method for observing a three-dimensional potential exerted on a single particle is proposed. A microparticle trapped by a focused Nd:YAG laser beam is irradiated with the evanescent field of a He-Ne laser under the total-internal reflection condition. The scattered light from the microparticle is detected by a quadrant photodiode, so that the differential outputs determine the position with nanometer resolution and the total intensity gives the separation distance between the quartz surface and the particle on the basis of the exponential dependence of the scattered evanescent-field intensity. Temporal fluctuation of the particle position resulting from the thermal Brownian motion is sequentially measured to obtain a histogram.
|Number of pages||1|
|State||Published - 1 Jan 1997|
|Event||Proceedings of the 1997 Conference on Quantum Electronics and Laser Science, QELS - Baltimore, MD, USA|
Duration: 18 May 1997 → 23 May 1997
|Conference||Proceedings of the 1997 Conference on Quantum Electronics and Laser Science, QELS|
|City||Baltimore, MD, USA|
|Period||18/05/97 → 23/05/97|