Photo fibers: Cross-sections of two polymer fibers, each less than a millimeter in diameter, show eight light sensors (gray rectangles) made of semiconducting material. The micrographs show two possible configurations for the sensors.
Optical fibers replace lenses.
Source: “Exploiting Collective Effects of Multiple Optoelectronic Devices Integrated in a Single Fiber”
Yoel Fink et al.
Nano Letters 9: 2630-2635
Results: Researchers at MIT have found a way to take photographs with polyester fibers. They integrated eight photodetectors into the fibers, arranged the fibers into a 32-by-32 grid spread over an area the size of a record album, and used the grid to capture a black-and-white image of a smiley face.
Why it matters: A standard camera requires lenses, which are rigid and fragile and can be heavy. A camera made from fibers, however, could be foldable, durable, and lightweight. In one potential application, it could be integrated into soldiers’ uniforms to create images of the surrounding environment.
Methods: Lenses focus scattered light to form an image. In the absence of a lens, measurements of the intensity of the scattered light can be used to computationally derive an image. To “photograph” the smiley face, the researchers illuminated it with laser light at different wavelengths, green and red. The photodetectors, embedded in a ring within each fiber, were able to distinguish light from each laser. After measuring the relative intensity of the colors, the researchers were able to apply algorithms that calculated the phase of the lightwaves scattered by the face. A separate algorithm used the phase information to reconstruct the image.
Next steps: The researchers plan to add more sensors to the fibers so that they can make images of objects illuminated with natural light. This could also lead to a color camera.