BETTER THAN SYSTEM LENS SKIN
BETTER THAN SYSTEM LENS SOFTWARE

вЂњLight scattering may seem detrimental to imaging, but in fact a scattering system can make an almost perfect lens.Figure 2: Side Profile Comparison of a Plano-Convex (PCX) and a Fresnel Lens MANUFACTURING FRESNEL LENSES Ultimately, he says, the technique could improve surgeonsвЂ™ views of what to cut during keyhole surgery. He hopes to see a hybrid system that combines his resolution with ChoiвЂ™s speed and field of view. вЂњI know of no other compact optical system that combines such high resolution with a field of view that large,вЂќ says Mosk. вЂњIt brings the concept of scattering lenses a big step closer to application for wide-area microscopy.вЂќ вЂњIt is very nice work,вЂќ says Jochen Aulbach at the FOM Institute for Atomic and Molecular Physics in Amsterdam, the Netherlands. вЂњOur system can perform wide-field imaging by converting a distorted image into a clean image using the recorded transmission matrix,вЂќ says Choi. This is because rays of light reflected from the target at angles too wide to be intersected by normal lenses are bent into a detector by the scattering lens (see diagram). The technique provided a field of view five times as wide as a traditional lens. This allowed them to piece together a detailed picture of the cell (right image).

BETTER THAN SYSTEM LENS SOFTWARE

They used pattern-matching software to sort through the 20,000 images to determine which regions of the matrix were in front of the cell. Then they placed a microglial cell from a ratвЂ™s brain behind the skin-lens and took another image (see left image).

BETTER THAN SYSTEM LENS SKIN

This provided a detailed 3D model of the skin sampleвЂ™s transmission matrix.

First they illuminated it from different angles, capturing around 20,000 images of the resulting transmitted light in 40 seconds. They used a 450-micrometre-thick slice of fresh rat skin as a lens. In May, they imaged gold nanoparticles at a resolution of just 97 nanometres, to show that scattering lenses can image below the 200-nanometre limit of conventional optical lenses ( Physical Review Letters, DOI: 10.1103/PhysRevLett.106.193905). In 2010, the researchers showed that such a lens could focus light into a spot one-tenth the size of that produced by an ideal transparent lens of the same size, making the focus 10 times as sharp. They used this matrix to design the shape of the incoming light waves so that they scattered off the particles and came to a focus on the other side. By correlating input and output light, the researchers calculated a вЂњ transmission matrixвЂќ that defines how light is scattered by disordered particles in such a material.

In 2007, Allard Mosk and colleagues at Twente University in Enschede, the Netherlands, demonstrated that materials not normally transparent to optical wavelengths can be used to sharply focus what little light gets through. Such вЂњscatteringвЂќ lenses could one day be used to see individual living cells, replacing biopsies and improving surgical precision.

Light that passes through an opaque medium, such as an eggshell, can be reassembled in sharper detail and over a wider field of view than if it passed through a transparent lens alone. ITвЂ™S as if Humpty Dumpty was put back together again вЂ“ stronger than before.

Better than system lens