3 ms·

I think one of the problems would be miniaturization. Visible light is hundreds of nanometers, and X-ray photonics are still in it's infancy

by N1H1L 6y ago

entropicdrifter 6y ago
You aren't limited by the wavelength in terms of pure transmission and reception. Bass frequency sound waves are multiple feet long, yet earbuds transfer those frequencies just fine.
- derefr 6y ago
  A wave of sound is a wave of pressure — i.e. density. Sound waves are one-dimensional. You can have a material one atom thick in a vacuum, and it’ll transmit sound just fine, as long as that material has some elasticity to it. Light waves, on the other hand, are two- [linearly-polarized] or three- [circularly-polarized] -dimensional. They’re heading in one direction, and also wiggling side-to-side as they go. If light didn’t have a “thickness” — that is, if light could “sneak through” gaps narrower than its “diameter” — then 1. “Optical” fibre would be capable of acting as a waveguide for all frequencies, not just optical ones; and 2. the Faraday cage around a microwave wouldn’t prevent the microwaves from escaping. (You might think we’d also get universal antennas out of that, but no, antennas are a quantum thing—it’s not about squeezing through a gap, but about exciting an AC electric field in the material, so letting the whole wavelength hit the antenna actually causes the induced field to destructively interfere with itself. Think of an antenna as absorbing the wave “head-on”, rather than “side-on.” Your antenna needs to catch half the wave — node to anode to node — to get the highest-power signal out. But you don’t miss the wave entirely if you catch less. You just get a less powerful signal — it’s still possible to do useful work [like power an optical receiver, or decode an AM radio signal] with just a 1/Nth slice of each cycle of the wave.)
  - entropicdrifter 6y ago
    TIL, thanks!

I think one of the problems would be miniaturization. Visible light is hundreds of nanometers, and X-ray photonics are still in it's infancy

by N1H1L 6y ago

I think one of the problems would be miniaturization. Visible light is hundreds of nanometers, and X-ray photonics are still in it's infancy

entropicdrifter 6y ago

You aren't limited by the wavelength in terms of pure transmission and reception. Bass frequency sound waves are multiple feet long, yet earbuds transfer those frequencies just fine.

derefr 6y ago
A wave of sound is a wave of pressure — i.e. density. Sound waves are one-dimensional. You can have a material one atom thick in a vacuum, and it’ll transmit sound just fine, as long as that material has some elasticity to it. Light waves, on the other hand, are two- [linearly-polarized] or three- [circularly-polarized] -dimensional. They’re heading in one direction, and also wiggling side-to-side as they go. If light didn’t have a “thickness” — that is, if light could “sneak through” gaps narrower than its “diameter” — then 1. “Optical” fibre would be capable of acting as a waveguide for all frequencies, not just optical ones; and 2. the Faraday cage around a microwave wouldn’t prevent the microwaves from escaping. (You might think we’d also get universal antennas out of that, but no, antennas are a quantum thing—it’s not about squeezing through a gap, but about exciting an AC electric field in the material, so letting the whole wavelength hit the antenna actually causes the induced field to destructively interfere with itself. Think of an antenna as absorbing the wave “head-on”, rather than “side-on.” Your antenna needs to catch half the wave — node to anode to node — to get the highest-power signal out. But you don’t miss the wave entirely if you catch less. You just get a less powerful signal — it’s still possible to do useful work [like power an optical receiver, or decode an AM radio signal] with just a 1/Nth slice of each cycle of the wave.)
- entropicdrifter 6y ago
  TIL, thanks!