Slow Light Augmented Fabry-Perot Cavity for Enhanced Sensitivity in Measuring Frequency Shift

David D. Smith; Dustin Greenwood; Jason Bonacum; Ruoxi Zhu; Selim M. Shahriar; Zifan Zhou

REVIEW 2 major objections 5 minor 1 cited by

Slow Light Augmented Fabry-Perot Cavity for Enhanced Sensitivity in Measuring Frequency Shift

T0 review · 2 major / 5 minor · reviewed 2026-08-15 · deepseek-v4-flash

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Pith's one-line read A slow-light augmented Fabry-Perot cavity can measure a laser's frequency shift with a sensitivity enhancement factor near $1.4\times10^5$ relative to heterodyne detection, because each round trip reuses the slow-light medium.

desk verdict A useful finite-linewidth formalism for slow-light Fabry-Perot sensors, but the headline 1.4e5 enhancement is likely overstated because the model treats the cold-atom medium as filling the whole cavity while the paper itself says the atoms are localized. read the letter →

arxiv 2506.15885 v1 pith:TQQ5UYGE submitted 2025-06-18 physics.optics quant-ph

Ruoxi Zhu , Zifan Zhou , Dustin Greenwood , Jason Bonacum , David D. Smith , Selim M. Shahriar This is my paper · ORCID

classification physics.opticsquant-ph

keywords slowlightFabry-Perotcavityfrequencyshiftmeasurementsensitivityenhancementfactorlaserlinewidthcoldatomsminimummeasurableheterodynedetection

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 shows that putting a slow-light medium inside a Fabry-Perot cavity improves the sensitivity with which a laser's frequency shift is measured, and that the improvement can beat both conventional heterodyne detection and a slow-light augmented unbalanced interferometer. A Fabry-Perot cavity is inherently unbalanced because successive round trips traverse different lengths before interfering, so the slow-light medium is effectively used once per bounce and the useful interaction length is multiplied by the finesse. The authors derive the cavity transfer function with a finite laser linewidth modeled as random phase jumps, obtain the minimum measurable frequency shift under shot noise, and express the result as a sensitivity enhancement factor depending on group index $n_g$, finesse $F$, and the laser coherence time. Absorption inside the slow-light medium hurts the cavity more than the interferometer, but for a cold-atom medium with $n_g = 10^6$ and roughly 3% loss per pass, the model predicts an enhancement factor near $1.4\times10^5$.

What carries the argument

The load-bearing object is the finite-linewidth cavity transfer function $H(\tilde{\omega}) = a(Q)\,\gamma_{\mathrm{SL}}^2/(\tilde{\omega}^2 + \gamma_{\mathrm{SL}}^2)$, with $\gamma_{\mathrm{SL}} = \gamma_{\mathrm{EC}}/n_g$ and $Q = L/(c\tau_c)$, where $\gamma_{\mathrm{EC}}$ is the empty-cavity half-width at half maximum, $n_g$ is the group index of the slow-light medium, $L$ is the cavity length, and $\tau_c$ is the laser coherence time. The algebraic factors $a(Q)$ and $b(Q)$, obtained by summing the attenuated interferences among all pairs of round trips, carry the finite-linewidth degradation. This transfer function converts the multi-bounce structure of a Fabry-Perot cavity into an effective slow-light path length multiplied by the finesse, and it is the object from which the minimum measurable frequency shift and the sensitivity enhancement factor are computed.

What would settle it

Measure the transfer function and the minimum measurable frequency shift of a working SLAFPC with a cold-atom slow-light medium while independently varying cavity length, finesse, group index, and laser linewidth; if the linewidth penalty follows $Q = n_g L/(c\tau_c)$ rather than $Q = L/(c\tau_c)$, the enhancement will roll off with finesse much earlier than predicted and the SEF near $1.4\times10^5$ will not appear.

Watch

Extended reading notes

Core claim

The central claim is that the steady-state output of a slow-light augmented Fabry-Perot cavity follows a transfer function of the form $H(\tilde{\omega}) = a(Q)\,\gamma_{\mathrm{SL}}^2/(\tilde{\omega}^2+\gamma_{\mathrm{SL}}^2)$, where $\tilde{\omega}$ is the deviation from a cavity resonance, $\gamma_{\mathrm{SL}} = \gamma_{\mathrm{EC}}/n_g$ is the empty-cavity linewidth narrowed by the group index, and $Q = L/(c\tau_c)$ measures how much the laser decoheres in one round trip. The coefficients $a(Q)$ and $b(Q)$ encode the interference between all pairs of round trips after averaging over random phase jumps. From this transfer function, the minimum measurable frequency shift under shot noise is inversely proportional to $n_g$ times a finesse-dependent factor, and the sensitivity enhancement factor over heterodyning grows with finesse while the laser remains coherent over a round trip. With a cold-atom slow-light medium at $n_g = 10^6$, a per-pass transmission near 0.97, and a finesse of 313, the predicted enhancement factor is about $1.4\times10^5$. The same model shows that intra-cavity absorption degrades this enhancement more severely than it degrades the interferometer version, because the light passes through the slow-light medium many times.

Load-bearing premise

The entire enhancement estimate assumes that the laser's random phase jumps pass through the slow-light medium at the vacuum speed of light, not at the slowed group speed; if the jumps were carried along at the group velocity, the decoherence parameter $Q$ would be roughly $n_g$ times larger and the predicted sensitivity gain would shrink.

Editorial extensions

If this is right

A frequency-shift sensor built on the SLAFPC could reach a sensitivity enhancement factor near $1.4\times10^5$ over heterodyne detection using a cold-atom cell, a finesse-313 cavity, and a standard test laser.
For the same group index and lossless mirrors, the cavity version beats the slow-light interferometer by roughly the finesse, since each of the many bounces reuses the slow-light medium.
The laser coherence time sets a practical ceiling: high finesse helps only while the round-trip time stays well below the coherence time, so a noisier laser requires a shorter cavity or a lower finesse.
Per-pass absorption is a sharper constraint for the cavity than for the interferometer, so the viable design space is high group index with only a few percent loss per pass.
Because the technique measures any laser frequency shift, the same cavity readout could improve ring-laser gyroscopes, accelerometers, and searches for ultralight dark matter.

Reading between the lines

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

A direct test of the vacuum-speed phase-jump assumption is to change only the physical cavity length at fixed group index and watch where the sensitivity peak occurs: vacuum-speed jumps predict a peak that tracks $L/c$, while group-speed jumps predict a peak that tracks $n_g L/c$.
The same $a(Q)$ and $b(Q)$ linewidth machinery should transfer to whispering-gallery and microring resonators, with the finesse replaced by the quality factor, giving a testable design rule for the optimal quality factor at a given laser linewidth.
Because the minimum-measurable-frequency-shift derivation is shot-noise limited, a real high-finesse implementation may hit cavity-length jitter or thermal noise first, so the practical optimum finesse could be lower than the lossless optimum highlighted in the paper.

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Editorial analysis

A structured set of objections, weighed in public.

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

Desk Editor's Note

read the letter

The genuinely new thing here is the finite-linewidth, shot-noise-limited treatment of a slow-light Fabry-Perot cavity. The transfer function is derived from the cavity equations, not assumed, and the scaling SEF ~ n_g F is plausible. The authors also correctly point out that the FPC is inherently unbalanced, and their comparison with the SLAUMZI, while based on their own earlier preprint, is a parameter-free derivation rather than a fit. That part is worth engaging with. Credit where due: the paper does not hand-wave the laser linewidth; modeling it as random phase jumps that propagate at the phase velocity is a reasonable physical assumption for instantaneous jumps, and the finite-Q corrections are worked out explicitly.

The soft spots, in order of importance. First, the localized-medium problem: Eq. (7) and the headline SEF in Fig. 7(d) use n_g = 1e6 as if the slow-light medium fills the entire cavity, but footnote [34] says a cold-atom ensemble would be localized. For a localized cloud of length l_m in a cavity of length L, the round-trip phase derivative is proportional to 1 + (l_m/L)(n_g - 1), not n_g. For l_m = 1 cm and L = 0.3 m, the effective group index is ~3.3e4, not 1e6, so the claimed SEF drops by roughly a factor of 30. This is not an experimental nitpick; the manuscript flags the geometry itself and then does not model it. Second, Eq. (22) locates the maximum Lorentzian slope at omega_tilde = gamma_SL; the actual maximum is at gamma_SL/sqrt(3). The MMFS and SEF change by about 1.3, a minor O(1) error but still an error. Third, the comparison with SLAUMZI relies on an unpublished preprint (Ref. [17]) for the baseline formula; that is defensible but makes the comparison harder to verify independently. Fourth, there is no experiment, so the 1.4e5 number remains a theoretical estimate, and the loss model uses optimistic parameters.

Overall: the formal machinery is solid enough to deserve referee time, and the concept is a legitimate extension of Shi et al. But the headline quantitative claim needs to be recomputed with a filling fraction, the Lorentzian slope error fixed, and the comparison to SLAUMZI made with the same geometric assumptions. After those revisions, the paper would be a credible contribution to precision frequency-shift metrology. I would not cite it in its current form, but I would send it to peer review with a request for major revision.

Referee Report

2 major / 5 minor

Summary. The paper derives an analytic model for a slow-light-augmented Fabry-Perot cavity (SLAFPC) and uses it to estimate the minimum measurable frequency shift (MMFS) of a laser, relative to conventional heterodyne detection. The transfer function is first obtained for an ideal, delta-function laser, then extended to a finite-Lorentzian-linewidth laser via the round-trip summation method with random phase jumps. The MMFS is computed from the maximum slope of the cavity transfer function, and the sensitivity enhancement factor (SEF) is compared with that of a slow-light-augmented unbalanced Mach-Zehnder interferometer (SLAUMZI) from the authors' prior work. Absorption is then included, leading to the central quantitative claim that for a cold-atom slow-light medium with group index n_g = 10^6, finesse F = 313, and ~3% loss per pass, an SEF of about 1.4 x 10^5 is achievable.

Significance. If correct, the result would be of genuine interest to the slow-light sensing community: it provides a self-contained analytic derivation of a new sensor configuration, gives closed-form expressions for the MMFS and SEF with no fitted free parameters, and makes a falsifiable quantitative prediction (SEF ~1.4 x 10^5 for stated parameters). The comparison with the SLAUMZI is based on the analytic formula from the authors' preprint [17], not on curve fitting, so the comparison is not circular. The central limitation is that the quantitative model assumes the slow-light medium fills the cavity, while the manuscript itself concedes that a cold-atom ensemble would be localized; this gap must be fixed before the headline claim is supported.

major comments (2)

[§4, Eq. (22)] The maximum of |dS/dω| for the Lorentzian line shape of Eq. (20) occurs at ω̃ = γ_SL/√3, not at ω̃ = γ_SL. Repeating the shot-noise-limited calculation at the true extremum gives MMFS = (4/3) γ_SL / sqrt(S_0 a(Q)) instead of the claimed 2 γ_SL / sqrt(S_0 a(Q)), so the MMFS is overestimated and the SEF underestimated by a factor of 3/2. Equations (23), (25), (28), and the numerical results in Figures 4–7 should be recomputed with the corrected coefficient.
[§2b and footnote [34]] The derivation following Eq. (7) treats the slow-light medium as filling the entire cavity, scaling the detuning by n_g and narrowing the HWHM to γ_SL = γ_EC/n_g. The manuscript explicitly notes in footnote [34] that a cold-atom ensemble would be localized in the SLAFPC, and §2b promises a 'simple modification' for partial filling that is never provided. For a medium of length l_m inside a cavity of length L, the round-trip phase derivative is proportional to 1 + (l_m/L)(n_g - 1), so the effective group index is 1 + (l_m/L)(n_g - 1), not n_g. With l_m = 1 cm and L = 0.3 m, the effective group index is reduced by about a factor of 30, and the headline SEF of ~1.4 x 10^5 in Figure 7(d) drops correspondingly unless n_g is increased. This gap is load-bearing for the central claim and should be fixed by writing the effective group index explicitly in Eqs. (7)–(8), (19), and (44) and recomputing Figures 6 and 7.

minor comments (5)

[§3, note after Eq. (19)] The assumption that instantaneous random phase jumps propagate at the vacuum phase velocity rather than the group velocity is plausible but should be justified more carefully or framed as a limiting assumption. For the STL-limited parameters used in the headline estimate, Q = τ_RT/τ_c is extremely small, so the finite-linewidth correction is nearly unity and this assumption does not significantly affect the main result.
[§2a, Eqs. (4)–(5)] The Lorentzian approximation in Eq. (4) actually has HWHM cT/(L√R), not cT/(LR) as stated. The relation between γ_EC, the finesse F, and the FSR in Eq. (5) should be checked; the numerical impact is small for R ≈ 0.99 but the formulas as written are not self-consistent.
[§5, Fig. 7 and Eq. (45)] The symbol Σ is used inconsistently: it is defined as the total round-trip attenuation factor for the cavity (Σ = σ³), but the text later refers to 'the attenuation factor per pass (Σ = σ³)'. For a localized cold-atom cloud, the number of passes through the medium per round trip differs from the uniformly filled case, so the mapping between σ and Σ should be clarified.
[§5, Fig. 7(d) caption and text] The star marking the SEF of ~1.4 x 10^5 is not explained in the caption; please state explicitly that it corresponds to n_g = 10^6, F = 313, and Σ = 0.97.
[Throughout] There are several typographical issues: 'Schwalow-Townes' should be 'Schawlow-Townes', and 'SLAPFC' in the discussion of Figure 7(d) should be 'SLAFPC'.

Circularity Check

0 steps flagged · score 0.0 of 10

No significant circularity: the SLAFPC sensitivity derivation is self-contained from the cavity equations; the SLAUMZI comparison is a prior parameter-free result, not a fitted input.

full rationale

The paper's core chain is a direct derivation: from the ring-cavity field recursion (Eqs. 1-2), the empty-cavity Airy transfer function (Eqs. 3-4), then a linear-dispersion slow-light modification in which n(ω) ≈ 1 + σω̃ leads to ω̃ → n_g ω̃ and hence γ̃_SL = γ̃_EC / n_g (Eqs. 6-8 and 19). The finite-linewidth treatment uses a stated phase-jump model with a Gaussian phase distribution and a single-summation transfer function (Eqs. 9-18); Q is defined, not fitted. The MMFS and SEF are then derived by standard shot-noise differentiation (Eqs. 20-29), and the absorption extension in Section 5 is a parameter redefinition of R and T. No parameter is fitted to data, and no 'prediction' is an input by construction. The comparison with the SLAUMZI uses Eq. (30) from the authors' prior work [17]; although self-cited, that result is a separate parameter-free analytic derivation and serves as a benchmark, not as the source of the SLAFPC enhancement. The localized-atom caveat in footnote [34] is a modeling limitation that may affect the quantitative headline, but it does not make the derivation circular.

Assumptions & free parameters 4 free parameters · 7 assumptions · 0 invented entities

The central formulas are parameter-free, but the numerical claims depend on assumed cold-atom parameters (n_g=10^6, F=313, 3% loss per pass). The derivation assumes a Lorentzian laser spectrum, instantaneous phase jumps, phase-velocity propagation of jumps, linear dispersion, shot-noise-limited detection, and lossless mirrors. No new entities are introduced.

free parameters (4)

group index n_g = 10^6 (assumed)
Chosen for the headline SEF of ~1.4e5, based on cold-atom EIT possibilities cited in Ref. [34]. The overall theory allows any n_g, but the numeric claim depends on this assumption.
finesse F = 313 (assumed)
Chosen for the star in Figure 7(d) and the headline SEF. Corresponds to mirror reflectivity R ~ 0.99.
attenuation factor per pass Sigma = 0.97 (assumed)
Assumed 3% loss per pass in a cold-atom slow-light medium. This value determines whether SLAFPC outperforms SLAUMZI in Figure 7.
laser output power and cavity length = 10 mW, 0.7 m (example)
Used to compute STL and photon rate in the numerical examples. The SEF depends on the ratio gamma_LC/gamma_EC, so these inputs affect the plotted SEF.

assumptions (7)

domain assumption Laser spectrum is Lorentzian with exponentially decaying two-time correlation
Stated in Section 3; needed for the single-summation transfer function of Eq. (16).
domain assumption Laser linewidth is fully represented by instantaneous random phase jumps
Stated after Eq. (19); required to substitute n_g omega_tilde into the finite-linewidth transfer function.
domain assumption Phase jumps propagate at phase velocity (vacuum speed) through the slow-light medium
Stated after Eq. (19); this sets Q = L/(c tau_c) and determines the linewidth degradation in the SLAFPC.
domain assumption Refractive index varies linearly with frequency around resonance
Used in Section 2b, Eqs. (6)-(7); valid for small frequency deviations in high-finesse cavities.
domain assumption Detection is shot-noise limited in the Schawlow-Townes limit
Used in Section 4, Eqs. (21)-(22) and footnote [31]; the authors note the MMFS formula would not hold for broader linewidths.
ad hoc to paper Cold atoms can provide n_g of about 10^6 with only 3% loss per pass
Invoked in Section 5, final paragraph, to claim the SEF of 1.4e5. This feasibility assumption is extrapolated from Ref. [34] and is not demonstrated in the paper.
domain assumption Cavity couplers are lossless with R + T = 1
Used in Section 2a for the empty cavity transfer function; dielectric coating complications are explicitly set aside in footnote [23].

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Cite this review

Pith. "Pith review of Slow Light Augmented Fabry-Perot Cavity for Enhanced Sensitivity in Measuring Frequency Shift." pith.science (2026). https://pith.science/paper/TQQ5UYGE

@misc{pith2026250615885,
  author       = {Pith},
  title        = {Pith review of: Slow Light Augmented Fabry-Perot Cavity for Enhanced Sensitivity in Measuring Frequency Shift},
  year         = {2026},
  howpublished = {\url{https://pith.science/paper/TQQ5UYGE}},
  note         = {Machine review of arXiv:2506.15885}
}

read the original abstract

Recently, it has been shown that a slow-light augmented unbalanced Mach-Zehnder interferometer (SLAUMZI) can be used to enhance significantly the sensitivity of measuring the frequency shift of a laser, compared to the conventional technique of heterodyning with a reference laser. Here, we show that a similar enhancement can be realized using a slow-light augmented Fabry-Perot Cavity (SLAFPC), due to the fact that an FPC is inherently unbalanced, since different bounces of the field traverse different path lengths before interfering with the other bounces. We show how the degree of enhancement in sensitivity depends on the spectral width of the laser and the finesse of the FPC. We also show how the sensitivity enhancement factor (SEF) for the SLAFPC is much larger than the same for the SLAUMZI for comparable conditions and the same group index, under lossless conditions. In general, the effect of the loss caused by the medium that produces the slow-light process is more prominent for the SLAFPC than the SLAUMZI. However, if the attenuation per pass can be kept low enough while producing a high group index, using cold atoms for generating the slow-light effect, for example, then the SEF for the SLAFPC can be much higher than that for the SLAUMZI. For potentially realizable conditions, we show that an SEF of ~1.4*10^5 can be achieved using a SLAFPC.

Figures

Figures reproduced from arXiv: 2506.15885 by the authors.

**Figure 1.** Schematic illustration of an empty Fabry-Perot resonator. The thickness ΔL of each reflector is assumed to be negligible. a b AR Coated AR Coated [PITH_FULL_IMAGE:figures/full_fig_p003_1.png] view at source ↗

**Figure 2.** Schematic illustration of a slow-light augmented Fabry-Perot cavity (FPC). Slow-light medium [PITH_FULL_IMAGE:figures/full_fig_p004_2.png] view at source ↗

**Figure 3.** Peak transmission as a function of the laser linewidth. Hpk [PITH_FULL_IMAGE:figures/full_fig_p007_3.png] view at source ↗

Figures from the paper (4 more)

**Figure 4.** Figure 4: The SEF as a function of the group index and the finesse in the SLAFPC and the SLAUMZI. Note that for the SLAUMZI the finesse is irrelevant, so that the SEF in that case does not vary with the finesse [PITH_FULL_IMAGE:figures/full_fig_p010_4.png]

**Figure 5.** Figure 5: The SEF as a function of laser coherence time for both the SLAFPC and the SLAUMZI by assuming the same operating condition. For the SLAFPC, the chosen ng and F are 1000 and 313, respectively. The measurement time for both cases is 0.1 sec. 0.2 0.4 0.6 0.8 1 exp(- 0 / (…

**Figure 6.** Figure 6: shows the SEF as a function of the finesse when ng = 103 , for three different values of σ , the attenuation factor for each arm. It can be seen from these plots that the inclusion of absorption significantly reduces the SEF. When the attenuation factor for each arm is…

**Figure 7.** Figure 7: , assuming the parameters of the input laser to be the same for both systems. The SEFs for both the SLAFPC and the SLAUMZI increase monotonically, as expected. For the higher finesse, the SEF for the SLAFPC falls below that of the SLAUMZI more rapidly as the value of σ…

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Forward citations

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Reviewed papers in the Pith corpus that reference this work. Sorted by Pith novelty score. Full citation record

The General Quantum Limit for and the Optimization of the Minimum Measurable Frequency Shift in a Laser
quant-ph 2026-07 conditional novelty 6.5 of 10

MMFS of an ideal laser is the RMS of spontaneous-emission phase diffusion and vacuum shot noise; optimized UMZI, FPC, and heterodyne sensors can reach ~sqrt(measurement bandwidth times STL).

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Works this paper leans on

27 extracted references · 27 canonical work pages · cited by 1 Pith paper

[34]

As such, the loss per pass woul d be the relevant factor to consider in that case

If an ensemble of cold at om is to be used, it would localized in the SLAFPC, rather than distributed over the whole cavity. As such, the loss per pass woul d be the relevant factor to consider in that case

work page
[4]

Ultrahigh enhancement in absolute and relative rotation sensing using fast and slow li ght,

M. S. Shahriar, G. S. Pati, R. Tripathi, V. Gopal, and M. Messall, “Ultrahigh enhancement in absolute and relative rotation sensing using fast and slow li ght,” Phys. Rev. A 75, 053807-1 - 053807-10 (2007)

work page 2007
[5]

Superluminal ring laser for hypersensitive sensing,

H. N. Yum, M. Salit, J. Yablon, K. Salit, Y. Wang, and M. S. Shahriar, “Superluminal ring laser for hypersensitive sensing,” Opt. Express 18(17), 17658 (2010)

work page 2010
[6]

Lasing dynamics of super and sub luminal lasers

J. Scheuer and S.M. Shahriar, “Lasing dynamics of super and sub luminal lasers”, Opt. Express 23, 32350– 32365 (2015)

work page 2015
[7]

Effect of Mult i-Order Harmonics in a Double-Raman Pumped Gain Medium for a Superluminal Laser,

Y. Wang, Z. Zhou, J. Yablon, and M. S. Sh ahriar, “Effect of Mult i-Order Harmonics in a Double-Raman Pumped Gain Medium for a Superluminal Laser,” Opt. Eng. 54(5), 057106 (2015)

work page 2015
[8]

Theoretical modeling and experimental demonstration of Raman probe induced spectral dip for realizing a superluminal laser,

J. Yablon, Z. Zhou, M. Zhou, Y. Wang, S. Tseng, and S.M. Shahriar, “Theoretical modeling and experimental demonstration of Raman probe induced spectral dip for realizing a superluminal laser,” Optics Express, Vol. 24, No. 24, 27446 (2016)

work page 2016
[9]

Fast-light Enhanced Brillouin Laser Based Active Fiber Op tic Sensor for Simultaneous Measurement of Rotation and Strain,

M. Zhou, Z. Zhou, M. Fouda, N.J. Condon, J. Scheuer, and M.S. Shahriar, “Fast-light Enhanced Brillouin Laser Based Active Fiber Op tic Sensor for Simultaneous Measurement of Rotation and Strain,” Journal of Lightwave Technology, 35 (23), 5222 (2017). 17

work page 2017
[10]

Effect of cascaded Brillouin lasing due to resonant pumps in a superluminal fibe r ring laser gyroscope,

M.F. Fouda, M. Zhou, H.N. Yum, and S.M. Shahriar, “Effect of cascaded Brillouin lasing due to resonant pumps in a superluminal fibe r ring laser gyroscope,” Opt. Eng. 57(10), 107108 (2018)

work page 2018

Show all 27 references

[11]

A superluminal Raman lase r with enhanced cavity length sensitivity,

Z. Zhou, M. Zhou and S.M. Shahriar, “A superluminal Raman lase r with enhanced cavity length sensitivity,” Optics Express 27, 29739-29745 (2019). [ 12 ] Y. Sternfeld, Z. Zhou, J. Scheuer, a nd M. S. Shahriar, “Electromagnetically induced transparency in Raman gain for realizin...

2019
[13]

Observation of a highly superluminal laser employing optically pumped Ra man gain and depletion,

Zifan Zhou, Nicholas Condon, Devin Hileman, and M. S. Shahriar, “Observation of a highly superluminal laser employing optically pumped Ra man gain and depletion,” Opt. Express 30, 6746-6754 (2022)

2022
[14]

Bi-directional Superluminal Ring Lasers wit hout Cross-talk and Gain Comp etition,

Z. Zhou, R. Zhu, N. Condon, D. Hileman, J. Bonacum and S.M. Sh ahriar, “Bi-directional Superluminal Ring Lasers wit hout Cross-talk and Gain Comp etition,” Appl. Phys. Lett. 120, 251105 (2022)

2022
[15]

Demonstration of a Superluminal Laser using El ectromagnetically Induced Transparency in Raman Gain,

Z. Zhou, R. Zhu, Y. Sternfeld, J. Scheuer, J. Bonacum, and S. M. Shahriar, “Demonstration of a Superluminal Laser using El ectromagnetically Induced Transparency in Raman Gain,” Opt. Express 31(9), 14377-14388 (2023)

2023
[16]

Single-pump ed gain profile for a superluminal ring laser,

Y. Sternfeld, Z. Zhou, S.M. Shahriar and J. Scheuer, “Single-pump ed gain profile for a superluminal ring laser,” Optics Express 31(22) 36952-36965 (2023). [17]R. Zhu, Z. Zhou, J. Li, J. Bonacum, D. D. Smith, and S. M. Shahriar, “Slow Light Augmented Unbalanced Interferometry ...

2023 doi arXiv
[18]

Aronowitz, in Laser Applications, edited by M

F. Aronowitz, in Laser Applications, edited by M. Ross (Academic, New York) pp. 113-200
[19]

Enhancing the spectral sensitivity of interferometers using slow-light media,

Z. Shi, Robert, W. Boyd, Daniel J. Gaut hier, and C. C. Dudley, “Enhancing the spectral sensitivity of interferometers using slow-light media,” Opt. Lett. 32, 915-917 (2007)

2007
[20]

Theory of the Linewidth of Semiconductor Lasers ,

C. H. Henry, “Theory of the Linewidth of Semiconductor Lasers ,” IEEE J. Of Quantum Electronics, Vol. QE-18, No. 2, (1982)

1982
[21]

Laser gyro at quantum limit

T.A. Dorschner, H.A. Haus, M. Holz, I.W. Smith, H. Statz, "Laser gyro at quantum limit", IEEE J. Quant. Elect. QE-16, 1376 (1980)

1980
[23]

Typically, dielectric coa tings would be used to generate such a reflectivity

In practice, the reflectivity of each coupler would be very hi gh in order to generate a large finesse. Typically, dielectric coa tings would be used to generate such a reflectivity. However, modeling the dielectric layers would require a level of complexity that is irrelevant...
[24]

Here, we have used the self-cons istent transfer function method instead

This result can also be obtained by using the alternative method of adding up an infinite number of reflections. Here, we have used the self-cons istent transfer function method instead. We use the alternative method later on when accounting for th e effect of the finite spect...
[25]

Meystre and M

P. Meystre and M. Sargent, Elements of Quantum Optics (1999), pp. 286–334

1999
[26]

G. S. Agarwal, in Springer Tracts in Modern Physics (1974), pp. 1–128

1974
[27]

Some applications of optical and infrared masers,

C. H. Townes, “Some applications of optical and infrared masers,” in Advances in Quantum Electronics, J.R. Singer., Ed., New York: Columbia Univ. Press, 1961, pp 1-11

1961
[28]

M. O. Scully and M.S. Zubairy, Quantum Optics, Cambridge University Press (1997)

1997
[29]

L ight speed reduction to 17 metres per second in an ultracold atomic gas,

L. V. Hau, S. E. Harris , Z. Dutton and C. H. Behrooz, “L ight speed reduction to 17 metres per second in an ultracold atomic gas,” Nature 397, 18 (1999) 18 [ 30 ] J. Capmany, J. Marti, and H. Mangrah am, “Impact of Finite Laser Linewidth on the Performance of OFDM Networks Em...

1999
[31]

In the more general case when the linewidth is broader than the STL, additional noise would be present

The fluctuation is shot noi se limited only in the limit where the laser linewidth is quantum noise limited, and given by the STL. In the more general case when the linewidth is broader than the STL, additional noise would be present. In such a case, again a detailed model of ...
[32]

Richter, H

L. Richter, H. Mandelberg, M. Kruger, and P. McGrath, IEEE Journal of Quantum Electronics 22, 2070 (1986)

1986
[33]

65 would not be valid, since additional sources of noise would have to be taken into accoun t

If we consider the general situation where the linewidth is broader than the STL, then the expression for the MMFS shown in Eqn. 65 would not be valid, since additional sources of noise would have to be taken into accoun t. As such, in estimating the SEF, we consider here the ...

Pith tools

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

[1] [34]

As such, the loss per pass woul d be the relevant factor to consider in that case

If an ensemble of cold at om is to be used, it would localized in the SLAFPC, rather than distributed over the whole cavity. As such, the loss per pass woul d be the relevant factor to consider in that case

work page

[2] [4]

Ultrahigh enhancement in absolute and relative rotation sensing using fast and slow li ght,

M. S. Shahriar, G. S. Pati, R. Tripathi, V. Gopal, and M. Messall, “Ultrahigh enhancement in absolute and relative rotation sensing using fast and slow li ght,” Phys. Rev. A 75, 053807-1 - 053807-10 (2007)

work page 2007

[3] [5]

Superluminal ring laser for hypersensitive sensing,

H. N. Yum, M. Salit, J. Yablon, K. Salit, Y. Wang, and M. S. Shahriar, “Superluminal ring laser for hypersensitive sensing,” Opt. Express 18(17), 17658 (2010)

work page 2010

[4] [6]

Lasing dynamics of super and sub luminal lasers

J. Scheuer and S.M. Shahriar, “Lasing dynamics of super and sub luminal lasers”, Opt. Express 23, 32350– 32365 (2015)

work page 2015

[5] [7]

Effect of Mult i-Order Harmonics in a Double-Raman Pumped Gain Medium for a Superluminal Laser,

Y. Wang, Z. Zhou, J. Yablon, and M. S. Sh ahriar, “Effect of Mult i-Order Harmonics in a Double-Raman Pumped Gain Medium for a Superluminal Laser,” Opt. Eng. 54(5), 057106 (2015)

work page 2015

[6] [8]

Theoretical modeling and experimental demonstration of Raman probe induced spectral dip for realizing a superluminal laser,

J. Yablon, Z. Zhou, M. Zhou, Y. Wang, S. Tseng, and S.M. Shahriar, “Theoretical modeling and experimental demonstration of Raman probe induced spectral dip for realizing a superluminal laser,” Optics Express, Vol. 24, No. 24, 27446 (2016)

work page 2016

[7] [9]

Fast-light Enhanced Brillouin Laser Based Active Fiber Op tic Sensor for Simultaneous Measurement of Rotation and Strain,

M. Zhou, Z. Zhou, M. Fouda, N.J. Condon, J. Scheuer, and M.S. Shahriar, “Fast-light Enhanced Brillouin Laser Based Active Fiber Op tic Sensor for Simultaneous Measurement of Rotation and Strain,” Journal of Lightwave Technology, 35 (23), 5222 (2017). 17

work page 2017

[8] [10]

Effect of cascaded Brillouin lasing due to resonant pumps in a superluminal fibe r ring laser gyroscope,

M.F. Fouda, M. Zhou, H.N. Yum, and S.M. Shahriar, “Effect of cascaded Brillouin lasing due to resonant pumps in a superluminal fibe r ring laser gyroscope,” Opt. Eng. 57(10), 107108 (2018)

work page 2018