<p>A study done by Michael A. Page, Maxim Goryachev, Haixing Miao, and peers states that WLCs can be used to improve the sensitivity of LIGO. LIGO currently uses photons (for very constant speed at which they travel in a vacuum), but if the phononic crystals were integrated into the structure of LIGO itself how would the phonons travel in a vacuum (considering they're mechanical waves). My physics teacher mentioned something about it travelling on the g-wave but refused to elaborate.</p>
<p>Link to Study (<a href="https://www.nature.com/articles/s42005-021-00526-2" rel="nofollow noreferrer">https://www.nature.com/articles/s42005-021-00526-2</a>)</p>
<p>Link to Article (<a href="https://theconversation.com/a-tiny-crystal-device-could-boost-gravitational-wave-detectors-to-reveal-the-birth-cries-of-black-holes-155125" rel="nofollow noreferrer">https://theconversation.com/a-tiny-crystal-device-could-boost-gravitational-wave-detectors-to-reveal-the-birth-cries-of-black-holes-155125</a>)</p>

CC BY-SA 4.0
2022-01-16T21:22:29.467Z
Well, the crystal isn't in the interferometer arms and it is still the interferometer that is generating the signal.
ProfRob
CC BY-SA 4.0
2022-01-16T21:52:00.790Z
@GursimranRandhawa the [phononic crystal](https://en.wikipedia.org/wiki/Acoustic_metamaterial) is a thin, mostly transparent sheet suspended transverse to the light beam inside the 30 cm long resonator ("negative dispersion filter cavity") shown at the bottom right of Figure 1 a/b of your linked [Page et al. 2021](https://www.nature.com/articles/s42005-021-00526-2) . It will certainly be vacuum inside that cavity outside of that thin sheet. As ProfRob points out, this cavity is a reflector in the recirculator, off to the side of the interferometer, not in it. I'm not sure if that helps though.
uhoh
CC BY-SA 4.0
2022-01-17T14:51:35.880Z
A quick skim of your links suggests that the photon-phonon interaction takes place entirely within the thin-sheet phononic crystal.  Think of that crystal as an amplifier/filter for all the photons which interact with it.
Carl Witthoft
<gravitational-waves><photons><quantum-mechanics><ligo>
How would white light cavities (WLC) work for gravitational wave detection?
Gursimran Randhawa
# How would white light cavities (WLC) work for gravitational wave detection?

(Asked by: username_0 on 2022-01-16)

A study done by Michael A. Page, Maxim Goryachev, Haixing Miao, and peers states that WLCs can be used to improve the sensitivity of LIGO. LIGO currently uses photons (for very constant speed at which they travel in a vacuum), but if the phononic crystals were integrated into the structure of LIGO itself how would the phonons travel in a vacuum (considering they're mechanical waves). My physics teacher mentioned something about it travelling on the g-wave but refused to elaborate.

Link to Study (<https://www.nature.com/articles/s42005-021-00526-2>)

Link to Article (<https://theconversation.com/a-tiny-crystal-device-could-boost-gravitational-wave-detectors-to-reveal-the-birth-cries-of-black-holes-155125>)

**Tags:** gravitational-waves, photons, quantum-mechanics, ligo

> **Comments:**
> **username_1**: Well, the crystal isn't in the interferometer arms and it is still the interferometer that is generating the signal.  
> **username_2**: @GursimranRandhawa the [phononic crystal](https://en.wikipedia.org/wiki/Acoustic_metamaterial) is a thin, mostly transparent sheet suspended transverse to the light beam inside the 30 cm long resonator ("negative dispersion filter cavity") shown at the bottom right of Figure 1 a/b of your linked [Page et al. 2021](https://www.nature.com/articles/s42005-021-00526-2) . It will certainly be vacuum inside that cavity outside of that thin sheet. As username_1 points out, this cavity is a reflector in the recirculator, off to the side of the interferometer, not in it. I'm not sure if that helps though.  
> **username_3**: A quick skim of your links suggests that the photon-phonon interaction takes place entirely within the thin-sheet phononic crystal.  Think of that crystal as an amplifier/filter for all the photons which interact with it.  

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## 0 answers

