Today’s clinicians are limited to a few imaging modalities, primarily X-ray, CT, MRI, and ultrasound. Microwaves, in principle, can also be used as a useful way to look inside the body. Microwave radiation is non-ionizing, so should be safer than X-rays, but in practice microwave imagers, because of the electronics inside, have remained bulky tabletop devices. Not only have they been impractical for imaging the body, the electronics inside conventional microwave imagers have suffered from interference.
Now, researchers at the University of Pennsylvania have developed a microwave imaging chip that replaces critical electronic components with optical ones, thereby allowing it to be much smaller and not suffer from as much interference.
The device is manufactured using now traditional semiconductor techniques resulting in a chip with over 1,000 photonic components, including waveguides and photodiodes. The device essentially works by converting microwave signals, that bounce back from the target, into optical ones. It then uses optical circuitry to process the data and generate an image of the target. It is only 2 millimeters on a side, so the components are microscopic.
Since the chip is about the size of one in your smartphone, it can be integrated into small, potentially hand-held devices to image the heart, spot cancer cells, and even look inside the brain.
Study in journal Optica: Single-chip nanophotonic near-field imager
Via: The Optical Society