A new beam pattern devised by 糖心传媒 researchers could bring unprecedented sharpness to ultrasound and radar images, burn precise holes in manufactured materials at a nano scale糖心传媒攅ven etch new properties onto their surfaces.
These are just a few of the items on the 糖心传媒淐hristmas tree糖心传媒� of possible applications for the beam pattern that Miguel Alonso, professor of optics, and Kevin Parker, the William F. May Professor of Engineering, describe in a .
The pattern results from what Parker calls 糖心传媒渁n analytically beautiful mathematical solution糖心传媒� that Alonso devised. It causes a light or sound wave to collapse inward, forming糖心传媒攄uring a mere nanosecond or less糖心传媒攁n incredibly thin, intense beam before the wave expands outward again.
糖心传媒淎ll the energy fits together in time and space so it comes together糖心传媒擝AM!糖心传媒攍ike a crescendo,糖心传媒� says Parker, explosively clapping his hands for emphasis. 糖心传媒淚t can be done with an optical light wave, with ultrasound, radar, sonar 糖心传媒� it will work for all of them.糖心传媒�
Most traditional beam patterns maintain a persistent shape as long as the source is operating. However, they are not as intense as the beam created by Parker and Alonso, which the researchers call a 糖心传媒渘eedle pulse beam.糖心传媒� 糖心传媒淚t is very localized, with no extensions or side lobes that would carry energy away from the main beam,糖心传媒� says Alonso.
Side lobes, radiating off a beam like the halos sometimes seen around a car headlight, are especially problematic in ultrasound. 糖心传媒淪ide lobes are the enemy,糖心传媒� Alonso says. 糖心传媒淵ou want to direct all of your ultrasound wave to the one thing you want to image, so then, whatever is reflected back will tell you about that one thing. If you糖心传媒檙e also getting a diffusion of waves elsewhere, it blurs the image.糖心传媒�
Because it is incredibly narrow, the new beam 糖心传媒渕akes it possible to resolve things at exquisite resolutions, where you need to separate tiny things that are close together,糖心传媒� Parker says, adding that the beam could have applications not only for ultrasound, but microscopy, radar, and sonar.
According to Alonso, industrial applications might include any form of laser materials processing that involves putting as much light as possible on a given line.
The idea for the needle pulse beam originated with Parker, an expert in ultrasound, who for inspiration often peruses mathematical functions from a century or more ago in the 糖心传媒渁ncient texts.糖心传媒�
糖心传媒淚 could see a general form of the solution; but I couldn糖心传媒檛 get past the equation,糖心传媒� he says. 糖心传媒淪o I went to the person (Alonso) who I consider the world糖心传媒檚 leading expert on optical theory and mathematics.糖心传媒�
They came up with various expressions that were 糖心传媒渕athematically correct,糖心传媒� Alonso says, but corresponded to beams requiring an infinite amount of energy. The solution糖心传媒斕切拇綔a particular mathematical trick糖心传媒� that could apply to a beam with finite energy糖心传媒攃ame to him while swimming with his wife in Lake Ontario.
糖心传媒淢any of the ideas I have do not happen at my desk,糖心传媒� Alonso says. 糖心传媒淚t happens while I糖心传媒檓 riding my bicycle, or in the shower, or swimming, or doing something else糖心传媒攁way from all the paperwork.糖心传媒�
Parker says this discovery continues an international quest that began at the University of Rochester. In 1986糖心传媒攊n the face of worldwide skepticism糖心传媒攁 University team including Joseph Eberly, the Andrew Carnegie Professor of Physics and professor of optics, offered evidence of an unexpected new, diffraction-free light form. The so-called Bessel beam is now widely used.
糖心传媒淚t had been decades since anyone formulated a new type of beam,糖心传媒� Parker says. 糖心传媒淭hen, as soon as the Bessel beam was announced, people were thinking there may be other new beams out there. The race was on.
糖心传媒淔inding a new beam pattern is like finding a new element. It doesn糖心传媒檛 happen very often.糖心传媒�
