By Ctein
You want to be sitting down for this one.
I’ve made pretty clear my heartfelt belief that the future will lie in informational optics and computational photography and that photographic technology will end up looking almost unimaginably different from what we’ve been using for 150 years.
But, here’s something I didn’t imagine, and sure wasn’t expecting it now. On the unbelievable/cool scale, it’s definitely a 10. We might even have to write an 11 on the dial. For your edification and amazement, two references:
“MIT develops camera-like fabric“
“Exploiting Collective Effects of Multiple Optoelectronic Devices Integrated in a Single Fiber“
Partial Abstract: “We show that a tandem arrangement of subwavelength photodetecting devices integrated in a single fiber enables the extraction of information on the direction, wavelength, and potentially even color of incident radiation over a wide spectral range in the visible regime. Finally, we fabricated a 0.1 square meter single plane fiber assembly which uses polychromatic illumination to extract images without the use of a lens, representing an important step toward ambient light imaging fabrics.”
Simple description: It’s a fabric, woven out of light-sensitive fibers, that can make a photograph. All by itself. No lens. No camera. No nuthin’.
(Well, it is backed by a honking big load of computing. In 10 years, that will all be on a chip.)
Frankly, I didn’t want to pay $30 to download the whole paper, but the abstract tells me enough to let me reverse-engineer the basic idea.
Normal, everyday light, on the sub-wavelength scale, can interfere with itself; it acts like a well ordered set of waves. The interference patterns depend on both the wavelength and the direction the photons are coming from. Take Newton rings, for example. Get two shiny surfaces really close to each other, and you’ll see bands of bright and dark colors.
Newton rings tell us a lot about the light that creates them. That pattern depends on the distance the light has to travel between the surfaces, measured in wavelengths. The shorter the wavelength, the closer the bands appear together. The shallower the angle of incidence, the farther apart the bands appear. In other words, that pattern of light and dark bands contains information about the direction the light is coming from and/or its wavelength.
That, I think, is the physics behind the fabric: It’s looking at the interference patterns within fibers, à la Newton rings, and from that, one can extract information about where the photons are coming from and what they’re like.
Which is just what a conventional camera lens and film/sensor does.
I can’t say how far this particular technology could be pushed; I just don’t know.
But just imagine…
It looks kind of like a Polaroid SX 70 print. Hold it up in front of you, grasping it by the lower right corner. An image of the scene the print “back” is facing appears on the side that you’re looking at. Squeeze the corner between your thumb and forefinger, and the print freezes the image.
Heck, let’s make the lower left corner a zoom control. There’s no reason we should be hobbled by a fixed “focal length” in our magic print; it’s all in the number crunching. Also, the print doesn’t “fix” the image until you squeeze the corner two times rapidly. Then it’s permanent. Otherwise, you can reuse the print, until you get a photograph you want to keep.
I told you you wanted to be sitting down for this one.