Assertion Supported AI assessment confidence: 90% certainty 4/5 debate potential 1/5

Adhikari: LIGO stabilizes lasers ten million times beyond commercial models

Rana Adhikari · The Technical Challenges of Measuring Gravitational Waves - Rana Adhikari of LIGO · Y Combinator · Sep 15, 2017 · at 18:55

Caltech physicist Rana Adhikari explains why commercial scientific lasers cannot be directly used in gravitational wave detectors without custom stabilization.

0:00 / 0:16exact quote · 16.3s

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“So we take the best laser in the world that we can find, and then we stabilize it and make it about ten million times more stable than what you can buy, and then it's kind of just barely good enough, and we're gonna have to do better if we want to do better.”

quote is from the automated transcript, cleaned for reading: filler sounds and stutters are removed, nothing is rephrased. names can be misheard (the analysis reads context, assessments check outside sources). how →

The claim, plainly

LIGO takes the best commercially available scientific laser and stabilizes its frequency to be approximately ten million times more stable than off-the-shelf units.

a quote alone can be ambiguous, so this restates it with the references and context of the conversation around it resolved. AI-written; the tape below the player is the source.

Assessment

Technical documentation and peer-reviewed design papers for LIGO's laser stabilization systems confirm that LIGO takes a commercially available master laser (a commercial non-planar ring oscillator Nd:YAG laser) and stabilizes its frequency across cascaded feedback control loops (the reference cavity pre-stabilization loop, input mode cleaner, and common-mode arm length loop). Specifically, published literature (such as Abbott et al., 2009) documents approximately 160 dB of frequency noise reduction at 100 Hz, which corresponds to an amplitude noise reduction factor of 10^8 (100 million times), fully supporting the approximate 'ten million times' (10^7) stability improvement stated by Rana Adhikari.

LIGO uses an off-the-shelf commercial Nd:YAG NPRO master laser with free-running frequency noise in the hundreds of Hz/sqrt(Hz) range at 100 Hz.
Abbott et al. (2009) report that LIGO's three cascaded frequency stabilization loops provide 160 dB of frequency noise reduction at 100 Hz, achieving frequency stability of 5 uHz rms in a 100 Hz bandwidth.
An amplitude reduction of 160 dB equates to a factor of 10^8 (100 million times reduction), corroborating the claim of approximately ten million times improved stability.

Checked against

[1] mtak.hu [2] ligo.org [3] mtak.hu [4] nsf.gov [5] ed-thelen.org [6] optica.org [7] lsu.edu [8] mpg.de

LIGO Pre-Stabilized Laser frequency noise Hz sqrt Hz master laser stabilized Advanced LIGO frequency stabilization free running NPRO reference cavity suppression LIGO PSL frequency stabilization noise reduction factor 10 7 Advanced LIGO pre stabilized laser frequency noise suppression factor master laser "LIGO" "frequency stabilization" "factor of" "10^7" OR "ten million" OR "10,000,000" OR "100,000,000" "frequency noise reduction" "LIGO" "100 Hz" "dB" OR "factor"

assessed as of 2026-09-05

This assessment is an AI reading of a public statement, made against the cited references with the confidence shown. It can be wrong. The quote, the tape and the references are all on this page; if something is off, use report an error below. full disclaimer →

Mentioned

laser LIGO

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Adhikari: LIGO stabilizes lasers ten million times beyond commercial models

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