{"id":367202,"date":"2019-04-02T11:04:29","date_gmt":"2019-04-02T15:04:29","guid":{"rendered":"http:\/\/www.rochester.edu\/newscenter\/?p=367202"},"modified":"2020-05-07T12:28:41","modified_gmt":"2020-05-07T16:28:41","slug":"optical-tweezers-nobel-prize-nanoparticles-367202","status":"publish","type":"post","link":"https:\/\/www.rochester.edu\/newscenter\/optical-tweezers-nobel-prize-nanoparticles-367202\/","title":{"rendered":"\u2018Optical tweezer\u2019 takes Nobel concept in a new direction"},"content":{"rendered":"
Thirty-three years ago, Arthur Ashkin showed how a very tightly focused laser beam attracts tiny particles towards it. When the laser beam moves, the particles move with it, held in the focus of the \u201coptical tweezer\u201d Ashkin created.<\/p>\n
This discovery, which earned Ashkin a share of the 2018 Nobel Prize in Physics, has since been applied in a variety of ways. For example, researchers have used optical tweezers to trap and sort healthy cells from infected ones.<\/p>\n
Now 做厙勛圖 and Rochester Institute of Technology scientists have found another use, which could shed new light on the fundamental properties of lasers\u2013and perhaps lead to better sensors and other devices.<\/p>\n
In a paper in Nature <\/em>Photonics<\/em>, they describe trapping nanoparticle-sized silica beads with an optical tweezer in a vacuum.<\/a> The oscillation of the beads is comprised of phonons\u2013basic units of vibrational energy. In addition, the beads cause some of the laser light to scatter. By measuring the scattered light, the researchers are then able to alter the way the beads oscillate and increase the output of energy as measured in phonons.<\/p>\n \u201cIf we do it just right, we can cause an oscillation that starts at one amplitude, and becomes bigger and bigger, until we start to exhibit mechanical motion that is analogous to what you would see if you turned on an ordinary optical laser in our labs,\u201d says co-author Nick Vamivakas<\/a>, an associate professor of quantum optics and quantum physics at Rochester. He is also lead investigator of a $3 million, multi-university Office of Naval Research grant that is funding the research.<\/p>\n Because the tweezer is operating in a vacuum, \u201cwe can simulate the dynamics of an optical laser in a very controlled way,\u201d Vamivakas says. \u201cIt will allow us to learn about lasers in a way that wouldn\u2019t be possible otherwise.\u201d<\/p>\n In addition, because the tweezer enables precise measurements of nanoscale particles, Vamivakas is hoping it can be used to test the validity of some basic theories of quantum mechanics, such as quantum wavefunction collapse.<\/p>\n Vamivakas says his lab is still exploring possible practical applications\u2014such as sensors and accelerometers\u2014that could result from the new tweezer. \u201cIt\u2019s like when the laser was first discovered,\u201d Vamivakas says. \u201cNobody knew what the laser would actually be used for. At this point, it is the demonstration that matters.\u201d<\/p>\n