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REVIEW 4 major objections 5 minor 35 references

Demonstration of a next-generation wavefront actuator for gravitational-wave detection

T0 review · 4 major / 5 minor · reviewed 2026-08-15 · deepseek-v4-flash

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Pith's one-line read A full-scale prototype wavefront actuator, FROSTI, produces the designed annular surface deformation on a 40-kg LIGO test mass with low enough noise for LIGO A+.

desk verdict First real test of FROSTI shows the wavefront shaping works, but the claim that it meets LIGO's noise requirements leans on unmeasured model numbers that need direct verification. read the letter →

arxiv 2509.08766 v1 pith:FOVCINHV submitted 2025-09-10 astro-ph.IM gr-qc

Tyler Rosauer , Huy Tuong Cao , Mohak Bhattacharya , Peter Carney , Luke Johnson , Shane Levin , Cynthia Liang , Xuesi Ma
show 6 more authors
Luis Martin Gutierrez Michael Padilla Liu Tao Aiden Wilkin Aidan Brooks Jonathan W. Richardson
This is my paper · ORCID
classification astro-ph.IMgr-qc PACS 04.80.Nn95.55.Ym42.60.Jf
keywords FROSTIwavefrontactuatorgravitational-wavedetectorthermalcompensationnonimagingopticstestmassrelativeintensitynoisebackscatteredlight
verification ladder T0 review T1 audit T2 compute T3 formal

The pith

A machine-rendered reading of the paper's core claim, the machinery that carries it, and where it could break.

The reading

The paper reports the first experimental demonstration of FROSTI, a front-surface thermal wavefront actuator for gravitational-wave detectors. A full-scale prototype, operated in vacuum against a 40-kg LIGO end test mass, produces the designed annular heating pattern and the expected surface deformation: a measured peak optical path difference of 771 nm versus 654 nm from the finite-element model. The authors also show that the actuator's intensity noise, measured through cross-spectral analysis of two photodetectors over 39 hours, lies below the LIGO A+ sensitivity curve, and that modeled backscattered-light noise is at least three orders of magnitude below it. If these results hold, FROSTI offers a practical way to correct the higher-order thermal aberrations that otherwise limit laser power and squeezing in current and future detectors, including Cosmic Explorer.

What carries the argument

The central mechanism is the FROSTI actuator: a 400-mm-diameter aluminum-nitride heater ring inside a gold-coated, nonimaging elliptical trough that concentrates 3–14 µm greybody radiation into an annular pattern on the test mass's front surface. The design rests on two quantitative couplings: photothermal flexure noise (Eq. 2), which converts relative intensity noise into test-mass displacement via a modeled coefficient of $5.21\times10^{-14}$ m/W, and backscattered-light noise (Eqs. 3–4), which converts relative motion between the actuator and the mirror into phase noise and radiation-pressure noise through a modeled backscatter fraction $\epsilon=1.51\times10^{-23}$.

What would settle it

Measure the flexure noise directly by modulating the FROSTI power with a known sinusoidal signal and observing test-mass displacement with the interferometer readout, or by placing a second Hartmann sensor on the back surface; alternatively, measure the backscattered-light fraction in situ by injecting a 1064-nm probe beam and detecting the power recombining into the main beam. If either measurement exceeds the model prediction by more than a factor of 10, the projected noise margin could be erased.

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Extended reading notes

Core claim

FROSTI (FROnt Surface Type Irradiator) is an annular radiator mounted 5 cm in front of a test mass. A greybody source at up to 400°C emits 3–14 µm thermal radiation, which a nonimaging elliptical trough reshapes into an annular irradiance pattern on the mirror's reflective coating. The absorbed heat produces thermoelastic deformation and, in transmissive optics, thermorefractive lensing that counteract the distortions caused by the main laser's coating absorption. The prototype confirmed three required properties: the measured surface temperature map peaks at 5.26±0.03 K versus a 5.21 K FEA prediction; the measured wavefront OPD profile matches the model and reaches 771±7 nm; the RIN upper limit from a 39-hour cross-spectral measurement excludes coherent intensity noise at 99.7% confidence and lies below the A+ strain sensitivity; and the backscatter fraction is modeled at ε=1.51×$10^{-23}$, placing projected noise at least three orders below the A+ curve. Outgassing from the UHV-compatible materials meets LIGO requirements.

Load-bearing premise

The claim that FROSTI is quiet enough for LIGO A+ rests on unmeasured model estimates: the flexure-noise coupling coefficient and the backscattered-light fraction are not directly measured, only simulated.

Editorial extensions

If this is right

  • If FROSTI meets A+ requirements, the 40-kg test masses of LIGO A+ can be equipped with a front-surface actuator that corrects residual edge wavefront errors, reducing optical loss and enabling higher circulating power.
  • The same annular actuation can shift higher-order mode co-resonances (HOM7) out of the cavity resonance, improving power buildup and squeezing.
  • The measured RIN upper limit and modeled backscatter noise indicate that FROSTI adds displacement noise at least an order of magnitude below the A+ design sensitivity, so it would not degrade the detector's noise floor.
  • The UHV-compatible materials and outgassing rates make the actuator installable inside the detector vacuum without contaminating optics.
  • The demonstrated nonimaging design technique can generalize to more complex irradiance profiles (nested heater rings) needed for LIGO A# and Cosmic Explorer.

Reading between the lines

Editorial extensions of the paper, not claims the author makes directly.

  • The same nonimaging design technique could be applied to other high-power laser systems where thermal aberrations limit beam quality, provided the noise coupling is similarly low.
  • Because the noise estimates rely on the assumed seismic-relative-motion spectrum, a direct measurement of FROSTI-mounted motion relative to the test mass would replace the safety factor with empirical data, tightening the projected margin.
  • The cross-spectral RIN measurement method demonstrated here could become a standard certification tool for any thermally-based wavefront actuator proposed for precision interferometry.
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Editorial analysis

A structured set of objections, weighed in public.

Desk editor's note, referee report, and a circularity audit.

Referee Report

4 major / 5 minor

Summary. The paper presents FROSTI, a front-surface thermal wavefront actuator intended to correct higher-order aberrations on LIGO test masses. The authors report the design, a full-scale prototype, and tests on a 40-kg LIGO end test mass: thermal-camera measurement of the induced surface temperature map, Hartmann-sensor measurement of the induced optical path difference, a two-photodiode cross-spectral measurement of relative intensity noise, an outgassing test, and ray-trace/FEA projections of backscatter and flexure noise. The paper concludes that FROSTI can meet LIGO A+ requirements and is a pathway to A#/Cosmic Explorer. The wavefront actuation itself is directly demonstrated, but the 'extremely low effective displacement noise' claim is based on model-derived quantities that are not directly measured.

Significance. If validated, the FROSTI concept would address a recognized bottleneck: high-order wavefront control on the directly suspended test masses at megawatt circulating power. The experimental work is substantial and well matched to the claims in several respects: the actuator is full-scale, the wavefront deformation is measured on a real ETM with two independent diagnostics, the RIN measurement uses a long cross-spectral integration to push below single-detector noise, and the vacuum compatibility test is quantitative. The residual concern is that the noise-performance claim, which is central to the 'meets LIGO A+' statement, currently rests on an FEA bending coefficient and a ray-traced backscatter fraction rather than on measured values. The result is therefore significant as a demonstration, but its full performance claim is not yet established.

major comments (4)
  1. [§3.A.1, §3.A.2] The FEA model is not independently validated. In §3.A.1, the absorbed power (10.2 W) and the HR-coating infrared reflectivity (~0.15) are fitted to make a joint FEA model reproduce the same FLIR and Hartmann measurements that are later used to demonstrate agreement; the comparison in §3.A.2 is therefore not an independent test. In addition, the measured peak OPD of 771±7 nm differs from the modeled 654 nm by 18%, while the temperature peaks agree to about 1% (5.26±0.03 K versus 5.21 K). This discrepancy is not explained and is not propagated into the uncertainty of the model. Because Eq. (2) is derived from the same FEA framework, the unexplained discrepancy directly weakens confidence in the noise projections.
  2. [§3.B.1, Eq. (2), Fig. 8] The measured RIN curve is not a direct measurement of FROSTI-induced displacement noise. The red curve in Fig. 8 is obtained by propagating the measured RIN upper limit through the FEA-derived flexure coefficient in Eq. (2), 5.21e-14 m, for which no uncertainty or experimental verification is given. The text should state this explicitly and provide either an experimental measurement of the photothermal transfer function (e.g., modulated heating with interferometric readout) or a conservative bound on the coefficient before claiming that the intensity-noise path is demonstrated to meet A+.
  3. [§3.B.2, Eqs. (3) and (4), Fig. 9] The backscatter-noise conclusion rests entirely on an unmeasured ray-trace value. In §3.B.2, epsilon = 1.51e-23 is taken from Section 4 of the Supplemental Document, and the Fig. 9 margin of three orders of magnitude scales as sqrt(epsilon); an error of six orders of magnitude in epsilon would bring the projected curve to the A+ level. The applied safety factor of 10 on the seismic relative-motion spectrum does not cover this model uncertainty. A direct measurement of the backscattered fraction, or an experimentally validated upper bound, is needed before the 'meets LIGO A+' statement can be accepted.
  4. [Abstract and §4] The abstract's claim that the design 'can meet' LIGO requirements is broader than the demonstrated results. Section 4 states that the prototype's single annular profile is not sufficiently accurate for A# and Cosmic Explorer, and the A+ noise conclusion depends on the model-based projections flagged above. Please distinguish the directly demonstrated wavefront-actuation capability and RIN upper limit from the projected noise performance, and restrict the 'meets requirements' language accordingly.
minor comments (5)
  1. [§2.B, Eq. (1)] The symbols T and ν in Eq. (1) are not defined; define them explicitly and state the temperature used for the 'less than 0.4%' numerical estimate.
  2. [§3.B.1, Fig. 8] Specify the FROSTI operating power assumed when converting the measured RIN upper limit to strain units, since Eq. (2) scales linearly with P.
  3. [Supplemental Document] The Supplemental Document is referenced for the RIN CSD procedure, FEA parameters, and the backscatter calculation, but it is not included with the arXiv preprint; please provide it or move the essential details into an appendix.
  4. [Data availability] The data availability statement says the data are not publicly available; providing processed temperature maps, OPD curves, and RIN spectra would substantially improve reproducibility.
  5. [§3.B.2, Eqs. (3) and (4)] Define Γ (signal-recycling gain) and state the values of Parm and ξ(f) used so that Eqs. (3) and (4) can be reproduced by readers.

Circularity Check

1 steps flagged · score 2.0 of 10

Fitted FEA peak-temperature agreement is partially circular, but shape and noise estimates retain independent content; no load-bearing circularity.

  1. fitted input called prediction [Section 3.A.1, Figure 6]
    "we are able to constrain its effective broadband infrared reflectivity, at a 45◦ angle of incidence, to be approximately 0.15 by matching the surface temperature and wavefront sensor measurements to a joint FEA model of both effects. ... We find that the best-fit model most closely reproducing the FLIR and wavefront sensor measurements corresponds to 12.0 W of incident power, of which 10.2 W is absorbed. This results in a peak temperature difference of 5.21 K between the ETM’s center and outer radii, which is in close agreement with the measured value of 5.26±0.03 K."

    The FEA 'prediction' of the temperature profile is produced by fitting the absorbed power (10.2 W) and HR reflectivity (0.15) to the same FLIR and wavefront measurements that are then cited as confirmation. The peak temperature difference 5.21 K versus the measured 5.26 K is therefore the output of the fit, not an independent check. The shape of the spatial profile is not a fitted output because the irradiance profile is imposed from the design, so the circularity is partial and does not extend to the full wavefront-shape demonstration.

full rationale

The central experimental claim—that FROSTI produces the designed annular surface deformation on a real 40-kg LIGO ETM—is supported by direct Hartmann wavefront measurements compared with an FEA model. The only reduction-by-construction element is the peak-temperature agreement in §3.A.1, where model parameters are adjusted to match the same data and then presented as 'close agreement.' This does not invalidate the measured OPD shape, which is not a fitted quantity, and the reported 771 nm versus 654 nm peak OPD discrepancy shows the comparison is not forced. The noise projections in §3.B are forward estimates: the flexure coupling coefficient in Eq. (2) comes from an FEA model with stated assumptions, and the backscatter fraction epsilon = 1.51e-23 comes from ray tracing in the Supplemental Document; neither is tuned to the LIGO A+ sensitivity curve, so any concern is model risk rather than circularity. Self-citations [21] and [22] supply design targets and HOM7 requirements, but the measured actuator demonstration does not reduce to those citations. Overall circularity is minor and localized, not load-bearing.

Assumptions & free parameters 2 free parameters · 5 assumptions · 0 invented entities

The paper's central claims rest on two fitted parameters (absorbed power and coating reflectivity) and several model-based assumptions (irradiance profile shape, backscatter fraction, flexure coupling, relative motion) that are not directly measured in the prototype. These are typical for an engineering demonstration, but they mean the 'meets requirements' claim is partly extrapolation.

free parameters (2)
  • Absorbed FROSTI power = 10.2 W (12.0 W incident)
    Best-fit value chosen to match the measured surface temperature and wavefront OPD in the joint FEA model; the same value is then used to claim agreement between model and measurement.
  • HR coating infrared reflectivity at 45 degrees = 0.15
    Constrained by matching surface temperature and wavefront sensor measurements to a joint FEA model; no direct spectral measurement of the LIGO HR coating beyond 1064 nm.
assumptions (5)
  • domain assumption The FEA model assumes the applied irradiance profile is proportional to the design profile shown in Figure 3 (top middle).
    The actual irradiance distribution on the test mass was not directly measured; the validation depends on this proportionality to interpret the temperature and wavefront measurements. Entered in Section 3.A.1.
  • domain assumption Backscatter fraction epsilon = 1.51e-23 computed from ray tracing in Supplemental Document Sec. 4.
    Not experimentally measured; the scattered-light noise projection in Section 3.B.2 relies entirely on this model estimate.
  • domain assumption Flexure noise coefficient 5.21e-14 m in Eq. (2) obtained from an FEA model following Ref [24].
    The conversion from measured relative intensity noise to strain uses this modeled coupling, which is not verified by the prototype measurements.
  • domain assumption Relative motion spectrum between FROSTI and test mass is the BSC-ISI ST2 seismic noise multiplied by a safety factor of 10.
    Used in the backscatter noise estimate in Section 3.B.2; actual mechanical coupling in the final mounting is unknown.
  • domain assumption Steady-state heat transfer and material properties of Suprasil 3001 from literature are correct.
    Standard engineering assumption invoked in the FEA model in Section 3.A.1.

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Pith. "Pith review of Demonstration of a next-generation wavefront actuator for gravitational-wave detection." pith.science (2026). https://pith.science/paper/FOVCINHV

@misc{pith2026250908766,
  author       = {Pith},
  title        = {Pith review of: Demonstration of a next-generation wavefront actuator for gravitational-wave detection},
  year         = {2026},
  howpublished = {\url{https://pith.science/paper/FOVCINHV}},
  note         = {Machine review of arXiv:2509.08766}
}
abstract

In the last decade, the Laser Interferometer Gravitational-Wave Observatory (LIGO) and the European Virgo observatory have opened a new observational window on the universe. These cavity-enhanced laser interferometers sense spacetime strain, generated by distant astrophysical events such as black hole mergers, to an RMS fluctuation of a few parts in $10^{21}$ over a multi-kilometer baseline. Optical advancements in laser wavefront control are key to advancing the sensitivity of current detectors and enabling a planned next-generation 40-km gravitational wave observatory in the United States, known as Cosmic Explorer. We report the first experimental demonstration of a new wavefront control technique for gravitational-wave detection, obtained from testing a full-scale prototype on a 40-kg LIGO mirror. Our results indicate that this design can meet the unique and challenging requirements of providing higher-order precision wavefront corrections at megawatt laser power levels, while introducing extremely low effective displacement noise into the interferometer. This new technology will have a direct and enabling impact on the observational science, expanding the gravitational-wave detection horizon to very early times in the universe, before the first stars formed, and enabling new tests of gravity, cosmology, and dense nuclear matter.

Figures

Figures reproduced from arXiv: 2509.08766 by the authors.

Figure 1
Figure 1. LIGO’s thermal compensation system (TCS), shown for one 4-km arm cavity (the other arm is identical). The functions of the ring heaters (RH) encircling each test mass (ITM/ETM) and the compensation plate (CP) are described in the text and in further detail in Ref. [17]. The FROSTI devices (yellow) are a new front-surface wavefront actuator proposed in this work. density of the quantum noise as 10−r/20, where r is th… view at source ↗
Figure 3
Figure 3. Ray-tracing and finite-element simulations of the FROnt Surface Type Irradiator (FROSTI) designed to apply higher-order wavefront corrections to the LIGO test masses. Each actuator mounts 5 cm in front of the test mass and just outside its 34-cm di￾ameter (top left). It projects an annular radiation pattern onto the front surface of the test mass, where it is absorbed (top right). The resulting surface deformation p… view at source ↗
Figure 4
Figure 4. Photos of the FROnt Surface Type Irradiator (FROSTI) prototype, fabricated to scale for actuation on a 40-kg LIGO test mass. Left: The two “upper” and ”lower” reflector sections, which are joined to form an annular nonimaging elliptical trough. Center: The fully-assembled FROSTI prototype, looking towards the rear surface which faces away from the test mass. Right: Test configuration showing the positioning of the F… view at source ↗
Figures from the paper (4 more)
Figure 5
Figure 5. Figure 5: Experimental configuration used to test the FROSTI prototype in vacuum on a 40-kg LIGO ETM. The thermoelastic and thermorefractive responses of the ETM to the FROSTI heating profile are measured using a Hartmann wavefront sensor (HWS) and thermal imaging camera (FLIR).…
Figure 7
Figure 7. Figure 7: Left: FEA-generated map of the optical path difference (OPD) produced by the FROSTI irradiance profile shown in [PITH_FULL_IMAGE:figures/full_fig_p006_7.png]
Figure 9
Figure 9. Figure 9: Total projected strain noise due to 1064-nm laser light backscattering from the FROSTI surfaces. At all frequencies, the modeled scattered light noise is found to lie at least three orders of magnitude below the target sensitivity of LIGO A+. where Parm is the arm cavi…
Figure 10
Figure 10. Figure 10: Measured outgassing rate spectrum of the FROSTI prototype operating at 625 K (blue), in comparison to the sensi￾tivity limit imposed by the vacuum system’s background (red). The red square indicates an injected argon calibration line. The green circles indicate the lo…

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Works this paper leans on

35 extracted references · 20 canonical work pages

  1. [1]

    Observation of Gravitational Waves from a Binary Black Hole Merger,

    B. P . Abbott, R. Abbott, T. D. Abbott,et al., “Observation of Gravitational Waves from a Binary Black Hole Merger,” Phys. Rev. Lett.116, 061102 (2016). https://doi.org/10.1103/PhysRevLett.116.061102

    doi:10.1103/physrevlett.116.061102 2016

  2. [2]

    The A+ design curve,

    L. Barsotti, L. McCuller, M.Evans, and P . Fritschel, “The A+ design curve,” LIGO Technical Report LIGO-T1800042 (2018). https://dcc.ligo. org/LIGO-T1800042/public

    work page 2018

  3. [3]

    Report of the LSC Post- O5 Study Group,

    P . Fritschel, K. Kuns, J. Driggers,et al., “Report of the LSC Post- O5 Study Group,” LIGO Technical Report LIGO-T2200287 (2022). https://dcc.ligo.org/LIGO-T2200287/public

    work page 2022

  4. [4]

    A Horizon Study for Cos- mic Explorer: Science, Observatories, and Community,

    M. Evans, R. X. Adhikari, C. Afle,et al., “A Horizon Study for Cos- mic Explorer: Science, Observatories, and Community,” arXiv e-Print 2109.09882 (2021). https://doi.org/10.48550/arXiv.2109.09882

    arXiv doi:10.48550/arxiv.2109.09882 2021

  5. [5]

    A two per cent Hubble constant measurement from standard sirens within five years,

    H. Y . Chen, M. Fishbach, and D. E. Holz, “A two per cent Hubble constant measurement from standard sirens within five years,” Nature 562, 545–547 (2018). https://doi.org/10.1038/s41586-018-0606-0

    doi:10.1038/s41586-018-0606-0 2018

  6. [6]

    A Future Percent-level Measurement of the Hubble Expansion at Redshift 0.8 with Advanced Research Article 9 LIGO,

    W. M. Farr, M. Fishbach, J. Y e, and D. E. Holz, “A Future Percent-level Measurement of the Hubble Expansion at Redshift 0.8 with Advanced Research Article 9 LIGO,” The Astrophys. J. Lett.883, L42 (2019). https://doi.org/10.3847/ 2041-8213/ab4284

    work page 2019

  7. [7]

    A Comprehensive Measure- ment of the Local Value of the Hubble Constant with 1 km/s/Mpc Uncer- tainty from the Hubble Space Telescope and the SH0ES Team,

    A. G. Riess, W. Yuan, L. M. Macri,et al., “A Comprehensive Measure- ment of the Local Value of the Hubble Constant with 1 km/s/Mpc Uncer- tainty from the Hubble Space Telescope and the SH0ES Team,” The Astrophys. J. Lett.934, L7 (2022). https://doi.org/10.3847/2041-8213/ ac5c5b

    doi:10.3847/2041-8213/ 2022

  8. [8]

    Leveraging SN Ia spectroscopic similarity to improve the measurement of H0,

    Y . S. Murakami, A. G. Riess, B. E. Stahl,et al., “Leveraging SN Ia spectroscopic similarity to improve the measurement of H0,” arXiv e-Print 2306.00070 (2023). https://doi.org/10.48550/arXiv.2306.00070

    arXiv doi:10.48550/arxiv.2306.00070 2023

Show all 35 references
  1. [9]

    The fuzzball proposal for black holes,

    K. Skenderis and M. Taylor, “The fuzzball proposal for black holes,” Phys. Reports467, 117–171 (2008). https://doi.org/10.1016/j.physrep. 2008.08.001

    2008 doi

  2. [10]

    Tests for the existence of black holes through gravitational wave echoes,

    V. Cardoso and P . Pani, “Tests for the existence of black holes through gravitational wave echoes,” Nat. Astron.1, 586–591 (2017). https: //doi.org/10.1038/s41550-017-0225-y

    2017 doi

  3. [11]

    Quantum hair of black holes out of equilibrium,

    R. Brustein and A. J. M. Medved, “Quantum hair of black holes out of equilibrium,” Phys. Rev. D97, 044035 (2018). https://doi.org/10.1103/ PhysRevD.97.044035

    2018

  4. [12]

    Resonant Shattering of Neutron Star Crusts,

    D. Tsang, J. S. Read, T. Hinderer,et al., “Resonant Shattering of Neutron Star Crusts,” Phys. Rev. Lett.108, 011102 (2012). https: //doi.org/10.1103/PhysRevLett.108.011102

    2012 doi

  5. [13]

    On the measurement of a weak classical force coupled to a quantum-mechanical oscillator. I. Issues of principle,

    C. Caves, K. Thorne, R. Drever,et al., “On the measurement of a weak classical force coupled to a quantum-mechanical oscillator. I. Issues of principle,” Rev. Mod. Phys.52, 341–392 (1980). https://doi.org/10. 1103/RevModPhys.52.341

    1980

  6. [14]

    Quantum-mechanical noise in an interferometer,

    C. M. Caves, “Quantum-mechanical noise in an interferometer,” Phys. Rev. D23, 1693–1708 (1981). https://doi.org/10.1103/PhysRevD.23. 1693

    1981 doi

  7. [15]

    Squeezed vacuum states of light for gravitational wave detectors,

    L. Barsotti, J. Harms, and R. Schnabel, “Squeezed vacuum states of light for gravitational wave detectors,” Reports on Prog. Phys.82, 016905 (2018). https://doi.org/10.1088/1361-6633/aab906

    2018 doi

  8. [16]

    Quantum-Enhanced Advanced LIGO Detectors in the Era of Gravitational-Wave Astronomy,

    M. Tse, H. Yu, N. Kijbunchoo,et al., “Quantum-Enhanced Advanced LIGO Detectors in the Era of Gravitational-Wave Astronomy,” Phys. Rev. Lett.123, 231107 (2019). https://doi.org/10.1103/PhysRevLett. 123.231107

    2019 doi

  9. [17]

    Overview of Advanced LIGO adaptive optics,

    A. F . Brooks, B. Abbott, M. A. Arain,et al., “Overview of Advanced LIGO adaptive optics,” Appl. Opt.55, 8256–8265 (2016). http://doi.org/ 10.1364/AO.55.008256

    2016 doi

  10. [18]

    Sensitivity and per- formance of the Advanced LIGO detectors in the third observing run,

    A. Buikema, C. Cahillane, G. L. Mansell,et al., “Sensitivity and per- formance of the Advanced LIGO detectors in the third observing run,” Phys. Rev. D102, 062003 (2020). https://doi.org/10.1103/PhysRevD. 102.062003

    2020 doi

  11. [19]

    Point absorbers in Advanced LIGO,

    A. F . Brooks, G. Vajente, H. Y amamoto,et al., “Point absorbers in Advanced LIGO,” Appl. Opt.60, 4047 (2021). https://doi.org/10.1364/ AO.419689

    2021

  12. [20]

    LIGO’s quantum response to squeezed states,

    L. McCuller, S. E. Dwyer, A. C. Green,et al., “LIGO’s quantum response to squeezed states,” Phys. Rev. D104, 062006 (2021). https://doi.org/ 10.1103/PhysRevD.104.062006

    2021 doi

  13. [21]

    Post-O5 Thermal Modeling: A# TCS requirements,

    H. T. Cao, A. Brooks, K. Kuns,et al., “Post-O5 Thermal Modeling: A# TCS requirements,” LIGO Technical Report LIGO-G2300624 (2023). https://dcc.ligo.org/LIGO-G2300624/public

    2023

  14. [22]

    Active Wavefront Control for Megawatt Arm Power,

    J. W. Richardson, “Active Wavefront Control for Megawatt Arm Power,” LIGO Technical Report LIGO-G2200399 (2022). https://dcc.ligo.org/ LIGO-G2200399/public

    2022

  15. [23]

    LIGO interferometer operating at design sensitivity with application to gravitational radiometry,

    S. W. Ballmer, “LIGO interferometer operating at design sensitivity with application to gravitational radiometry,” Ph.D. thesis, Massachusetts Institute of Technology (2006). http://hdl.handle.net/1721.1/36396

    2006

  16. [24]

    TCS Actuator Noise Couplings,

    P . Willems, “TCS Actuator Noise Couplings,” LIGO Technical Report LIGO-T060224 (2011). https://dcc.ligo.org/LIGO-T060224/public

    2011

  17. [25]

    21 - Optoelectronics,

    G. E. Stillman, “21 - Optoelectronics,” inReference Data for Engineers, W. M. Middleton and M. E. Van Valkenburg, eds. (Newnes, 2002), pp. 21–1–21–31, 9th ed. https://doi.org/10.1016/B978-075067291-7/ 50023-6

    2002 doi

  18. [26]

    Central heating radius of curvature correction (CHRoCC) for use in large scale gravitational wave interferometers,

    T. Accadia, F . Acernese, M. Agathos,et al., “Central heating radius of curvature correction (CHRoCC) for use in large scale gravitational wave interferometers,” Class. Quantum Gravity30, 055017 (2013). https://doi.org/10.1088/0264-9381/30/5/055017

    2013 doi

  19. [27]

    Matrix heater in the gravitational wave observatory GEO 600,

    H. Wittel, C. Affeldt, A. Bisht,et al., “Matrix heater in the gravitational wave observatory GEO 600,” Opt. Express26, 22687–22697 (2018). https://doi.org/10.1364/OE.26.022687

    2018 doi

  20. [28]

    Winston, J

    R. Winston, J. Minano, P . Benitez,et al.,Nonimaging Optics (Elsevier Science, 2005), 1st ed. https://shop.elsevier.com/books/ nonimaging-optics/winston/978-0-12-759751-5

    2005

  21. [29]

    Asymmetric design for Compound Ellipti- cal Concentrators (CEC) and its geometric flux implications,

    L. Jiang and R. Winston, “Asymmetric design for Compound Ellipti- cal Concentrators (CEC) and its geometric flux implications,” inNon- imaging Optics: Efficient Design for Illumination and Solar Concen- tration XII,vol. 9572 R. Winston and J. M. Gordon, eds., Interna- tional S...

    2015 doi

  22. [30]

    The Holometer: an instru- ment to probe Planckian quantum geometry,

    A. Chou, H. Glass, H. R. Gustafson,et al., “The Holometer: an instru- ment to probe Planckian quantum geometry,” Class. Quantum Gravity 34, 065005 (2017). https://doi.org/10.1088/1361-6382/aa5e5c

    2017 doi

  23. [31]

    Noise Due to Backscatter Off Baffles, the Nearby Wall, and Objects at the Fare End of the Beam Tube; and Recommended Actions,

    E. Flanagan and K. Thorne, “Noise Due to Backscatter Off Baffles, the Nearby Wall, and Objects at the Fare End of the Beam Tube; and Recommended Actions,” LIGO Technical Report LIGO-T940063 (1994). https://dcc.ligo.org/LIGO-T940063/public

    1994

  24. [32]

    Scattered light noise due to the ETM coating ripple,

    P . Fritschel and H. Y amamoto, “Scattered light noise due to the ETM coating ripple,” LIGO Technical Document LIGO-T1300354 (2013). https://dcc.ligo.org/LIGO-T1300354/public

    2013

  25. [33]

    Seismic isolation of Ad- vanced LIGO: Review of strategy, instrumentation and performance,

    F . Matichard, B. Lantz, R. Mittleman,et al., “Seismic isolation of Ad- vanced LIGO: Review of strategy, instrumentation and performance,” Class. Quantum Gravity32, 185003 (2015). https://doi.org/10.1088/ 0264-9381/32/18/185003

    2015

  26. [34]

    Qualifying Parts for LIGO UHV Service,

    D. Coyne, “Qualifying Parts for LIGO UHV Service,” LIGO Technical Report LIGO-E1000088 (2010). https://dcc.ligo.org/LIGO-E1000088/ public

    2010

  27. [35]

    RGA Test Qualification of Components for the LIGO UHV,

    D. Coyne, “RGA Test Qualification of Components for the LIGO UHV,” LIGO Technical Report LIGO-E080177 (2020). https://dcc.ligo.org/ LIGO-E080177/public

    2020

Pith tools

Reviewed August 15, 2026 · model on record in the stance chip above.