3 ms·

It just seems tremendously inefficient. Power in vs useful power out is huge. What's stopping them from "just" making a uv laser? I'm guessing tin is the onl

• philipkglass 2y ago
  Semiconductors with direct band gaps like gallium nitride can be used to make light emitting diodes (both incoherent light and lasers). Gallium nitride emits light around 405 nanometers: https://en.wikipedia.org/wiki/Gallium_nitride https://en.wikipedia.org/wiki/Gallium_nitride The light wavelength is proportional to the band gap. GaN has a 3.4 electron volt band gap. To get a 13.5 nanometer emission, you'd need a direct band gap material in excess of 90 electron volts: https://www.kmlabs.com/en/wavelength-to-photon-energy-calculator https://www.kmlabs.com/en/wavelength-to-photon-energy-calcul... No such materials exist. The emission from tin in EUV light sources is actually from thermal (blackbody) radiation. The infrared lasers heat tin vapor to extremely high temperatures where it shines into the extreme ultraviolet. It's inherently wasteful but this extreme ultraviolet range is much harder to access than visible light or near ultraviolet.
  • hoseja 2y ago
    It's really weird that particle accelerators or just some sort of X-ray tubes are apparently even more bothersome than precisely exploding freefalling drops of liquid tin with heat rays.