Stanford University physicists were able to figure out how to make low-light microscopy clearer without risking damage on light-sensitive specimens. This is helpful for the research on proteins and internal structures.
According to Stanford University's official website, researchers were limited by low-light imaging for fear of damaging light-sensitive specimens. As a result, they only get photos filled with "shot noise," which is the effect that causes these grainy images.
Apparently, Stanford physicists have solved this problem through multi-pass microscopy. In a paper for "Nature Communications," multi-pass microscopy allows researchers "to form an image of enhanced contrast by re-imaging a pulse of light m times onto the sample."
"If you work at low-light intensities, shot noise limits the maximum amount of information you can get from your image," Thomas Juffmann, co-author of the research and a postdoctoral research fellow in Stanford Professor Mark Kasevich's research group, said. "But there's a way around that; the shot-noise limit is not fundamental."
Basically, the researchers have discovered that they actually get better results if each photon interacts with the sample several times, even when there is low-lighting. This is implemented with a microscope by repeatedly reflecting the image back onto the specimen instead of just sending light through the specimen and capturing the image.
Co-author Brannon Klopfer, a graduate student in the Kasevich group added that it is just like taking a picture of the object multiple times. "You first take an image of the specimen, you then illuminate it with an image of itself, and the image you get, you again send back to illuminate the sample," he said. "This leads to contrast enhancement."
It was also noted that multi-pass microscopy is not the only way to overcome the shot noise limit. Another technique is quantum microscopy that uses entangled photons to get the same results. The latter, however, is reportedly more challenging to carry out.
Stanford University has recently nabbed the top spot in The Wall Street Journal/Times Higher Education's Top College Rankings list. According to WSJ, students who want a school that will engage their minds, with a diverse student body and a school that has plenty of resources for their education should head to this school.
