OSA's Digital Library

Optics Express

Optics Express

  • Editor: C. Martijn de Sterke
  • Vol. 17, Iss. 12 — Jun. 8, 2009
  • pp: 9582–9587
« Show journal navigation

Ultra-stable, widely tunable and absolutely linked mid-IR coherent source

I. Galli, S. Bartalini, P. Cancio, G. Giusfredi, D. Mazzotti, and P. De Natale  »View Author Affiliations


Optics Express, Vol. 17, Issue 12, pp. 9582-9587 (2009)
http://dx.doi.org/10.1364/OE.17.009582


View Full Text Article

Acrobat PDF (275 KB)





Browse Journals / Lookup Meetings

Browse by Journal and Year


   


Lookup Conference Papers

Close Browse Journals / Lookup Meetings

Article Tools

Share
Citations

Abstract

We report on a new coherent source that, using a phase-lock scheme to an optical frequency-comb synthesizer, achieves a 10-Hz intrinsic linewidth, is tunable from 4 to 4.5 µm with a presettable absolute frequency and, when coupled to a high-finesse cavity, can provide a short-term absorption sensitivity of 1.3·10-11 cm-1Hz-1/2. These unique spectral features make this source a precise tool for molecular physics.

© 2009 Optical Society of America

1. Introduction

2. Experimental set-up

Our OFCS-referenced DFG source can generate 300-80 µWidler radiation at any wavelength between 3950 and 4570 nm. The significant variation in generated power is due to the 1/λ 2 i dependence of the nonlinear efficiency on the idler wavelength λi and to the absorption losses in LiNbO3, that finally set the long-wavelength edge[7

7. S. Borri, P. Cancio, P. De Natale, G. Giusfredi, D. Mazzotti, and F. Tamassia, “Power-boosted difference-frequency source for high-resolution infrared spectroscopy,” Appl. Phys. B 76, 473–477 (2003). [CrossRef]

]. Instead, tunability at shorter wavelengths can be easily extended by a proper choice of fiber lasers/amplifiers and/or different semiconductor lasers. A schematic of the DFG source is shown in Fig. 1. A 50-mm-long periodically-poled LiNbO3 (PPLN) crystal mixes about 100 mW pump radiation from an external-cavity diode laser (ECDL) with about 3.4Wsignal radiation from a Yb-fiber-amplified Nd:YAG laser at 1064 nm. The ECDL has a feedback diffraction grating moved by a piezo-electric transducer (PZT) and is tunable between 838 and 863 nm. In order to control the phase/frequency of the generated IR radiation against our fs Ti:sapphire OFCS, which covers an octave in the visible/near-IR region (500-1100 nm), we follow an electronic scheme based on direct digital synthesis (DDS)[29

29. H. R. Telle, B. Lipphardt, and J. Stenger, “Kerr-lens mode-locked lasers as transfer oscillators for optical frequency measurements,” Appl. Phys. B 74, 1–6 (2002). [CrossRef]

]. Both pump and signal frequencies are beaten with the closest tooth of the OFCS (the corresponding integer orders Np and Ns are measured by a wave-meter) and the respective RF beat notes Δνpc and Δνsc satisfy the following equations:

Fig. 1. OFCS-referenced DFG IR source. OFCS is used as a transfer oscillator to phase-lock the ECDL directly to the Nd:YAG. DM, dichroic mirror; Ge, germanium filter. See text for other acronyms.
Δνpc=νpNpνrνo
(1)
Δνsc=νsNsνrνo
(2)

where νr≈1 GHz is the repetition rate and νo is the OFCS carrier-envelope-offset (CEO), which is canceled from these beat notes by standard RF mixing. A low bandwidth (≈10 Hz) phase-locked-loop (PLL) is used to remove the frequency drift of the Nd:YAG laser. A DDS circuit multiplies the Δνsc+νo frequency by a factor Np/Ns. A second PLL circuit with a wide bandwidth (≈2 MHz) locks the Δνpc +νo frequency to the DDS output by sending feedback corrections to the ECDL current and PZT voltage. The pump frequency is then νp=(Np/Ns)νs, without any contribution from the OFCS parameters νo and νr (at least at frequencies >10 Hz). As a consequence, the absolute frequency νi of the generated idler radiation is given by the following equation:

νi=νpνs=(NpNs1)νs
(3)

The idler linewidth δνi can be expressed in terms of the signal linewidth δνs, as follows:

δνi=(NpNs1)δνs
(4)

3. Frequency stability and absorption sensitivity characterization

In order to test the frequency stability of this source and the achievable absorption sensitivity, we built a 1-m-long high-finesse cavity with maximum reflectivity at 4500 nm. The ZnSe plano-concave mirrors have a high-reflection coating on their concave surface (6 m radius of curvature) and an anti-reflection coating on the plane surface. Each mirror was measured to have 270 ppm losses (100 ppm absorption and 170 ppm transmission), corresponding to a finesse F≈11500. The transmitted power through the resonant cavity was about 35% of the incident one and the achieved mode-matching was 86%. The mirror holders are separated by a three-bar Invar structure which guarantees a good passive thermal stability. The whole structure lays inside a vacuum chamber with a cantilever system damping mechanical vibrations in all directions. The vacuum conditions prevent frequency fluctuations due to pressure changes. A three PZT system is mounted on one mirror for fine cavity tuning. In order to use this cavity as frequency noise discriminator of the IR source, we have characterized its passive frequency stability. The cavity drift of about 1 kHz/s was measured from the linewidth of the cavity transmission averaged over long time scales (about 500 s) when illuminated with the OFCS-locked DFG source, which has negligible drift in this time interval. At 100 Hz, the frequency noise induced by the PZT-driven electronics was measured to be one order of magnitude lower than the one of the IR source, and it decreases with a 1/f behavior up to 30 kHz. A resonance frequency of about 19 Hz and a damping time of about 5 s for the cantilever damped vibration system were measured by using an accelerometer. In Fig. 2 (a), we assigned the 19 Hz peak to the residual vibrational cavity noise at the cantilever resonance. Due to the narrow linewidth of this resonance, the noise amplitude falls by 15 dB at 20 Hz. For frequencies higher than 20 Hz, the vibrations are damped following a 1/f2 law in units of HzHz, as inferred by the solution of the differential equation for a damped harmonic oscillator forced by external vibration-induced white noise.

Fig. 2. (a) Frequency noise spectral density recorded with a FFT spectrum analyzer. Three spectra with different frequency spans (2 kHz, 10 kHz, 1 MHz) are stuck together and plotted in the same graph (RBW=3·10-3×span). (b) Typical single-shot cavity ring-down signal. The experimental data points, the exponential fit curve and the residuals are shown.

To characterize the frequency noise of our source, we tuned the cavity length at a transmission corresponding to half of the peak value and used the slope of the fringe side as a frequency-to-amplitude converter. The frequency noise spectral density recorded with a FFT spectrum analyzer is shown in Fig. 2 (a). The red lines highlight different behaviours of the spectrum: 1/f technical noise (ν<2 kHz), white noise (ν>2 kHz), cavity-cut-off region (ν>10 kHz), detector-cut-off region (ν>400 kHz). Following the above discussion about the cavity frequency stability, we can consider negligible the cavity contribution to this noise in the spectral range shown in the figure. From the power spectral density in the white-noise region we can infer an IR intrinsic linewidth[32

32. A. Yariv, Quantum electronics, 3rd ed. (Wiley, 1988).

] of about 10 Hz, while the time-integrated linewidth over 1 ms is about 1 kHz. In order to evaluate the signal-to-idler frequency noise transfer, we also applied a 8 kHz frequency modulation onto the Nd:YAG laser radiation, with known amplitudes Amod. In the frequency-to-amplitude cavity converted spectrum at 4500 nm, the peak at 8 kHz is observed with amplitudes of about (Np/Ns-1)Amod, in agreement with Eq. 3, confirming the negligible cavity contribution to the measured noise spectral density.

To measure the absorption sensitivity, we performed CW cavity ring-down (CRD) spectroscopy[33

33. D. Romanini, A. A. Kachanov, N. Sadeghi, and F. Stoeckel, “CW cavity ring down spectroscopy,” Chem. Phys. Lett. 264, 316–322 (1997). [CrossRef]

] with the empty cavity (pressure<10-5 mbar). The IR radiation is switched off in ≈200 ns by deflecting the pump beam with an acousto-optic modulator (AOM) in double-pass configuration. Fig. 2 (b) shows a single-shot CRD event, the exponential fit and the corresponding residuals. The standard error over 1/τ achieved in a measurement time T=100 µs (4·10-5 µs-1) yields an absorption sensitivity of 1.3·10-11 cm-1Hz-1/2. The shot-noise-limited minimum detectable absorption is expressed by the following equation[34

34. J. Ye, L.-S. Ma, and J. L. Hall, “Ultrasensitive detections in atomic and molecular physics: demonstration in molecular overtone spectroscopy,” J. Opt. Soc. Am. B 15, 6–15 (1998). [CrossRef]

]:

αmin=π2F1L2eBηP
(5)

where L=100 cm is the cavity length, B=1/(2πT) is the detection bandwidth, η≈2.5 A/W is the detector responsivity, P≈6 µW is the detected optical power. The calculated value αmin=8.0·10-12 cm-1Hz-1/2 is then very close to the experimental one. Actually, the achievable sensitivity over longer timescales is even two orders of magnitude worse than expected. We ascribe that discrepancy to shot-to shot geometry-dependent variations of τ, optical fringes, finite extinction ratio of the light modulator, similarly to what was observed by other groups performing CRD.

4. Conclusions

Acknowledgments

We wish to thank L. Lorini (INRIM, Italy) for the calibration of the frequency reference and R. Ballerini (LENS, Italy) for making the cavity. This work was partially supported by Ente Cassa di Risparmio di Firenze. This work, as part of the European Science Foundation EUROCORES Program EUROQUAM-CIGMA, was partially supported by founds from CNR and the other participating national Funding Agencies and the EC Sixth Framework Program.

References and links

1.

B. C. Young, F. C. Cruz, W. M. Itano, and J. C. Bergquist, “Visible lasers with subhertz linewidths,” Phys. Rev. Lett. 82, 3799–3802 (1999). [CrossRef]

2.

G. Rempe, R. J. Thompson, H. J. Kimble, and R. Lalezari, “Measurement of ultralow losses in an optical interferometer,” Opt. Lett. 17, 363–365 (1992). [CrossRef] [PubMed]

3.

S. A. Diddams, D. J. Jones, J. Ye, S. T. Cundiff, J. L. Hall, J. K. Ranka, R. S. Windeler, R. Holzwarth, T. Udem, and T. W. Hänsch, “Direct link between microwave and optical frequencies with a 300 THz femtosecond laser comb,” Phys. Rev. Lett. 84, 5102–5105 (2000). [CrossRef] [PubMed]

4.

T. Udem, R. Holzwarth, and T. W. Hänsch, “Optical frequency metrology,” Nature 416, 233–237 (2002). [CrossRef] [PubMed]

5.

T. W. Hänsch, “Nobel Lecture: Passion for precision,” Rev. Mod. Phys. 78, 1297–1309 (2006). [CrossRef]

6.

J. Nicholson, A. Yablon, P. Westbrook, K. Feder, and M. Yan, “High power, single mode, all-fiber source of femtosecond pulses at 1550 nm and its use in supercontinuum generation,” Opt. Express 12, 3025–3034 (2004). [CrossRef] [PubMed]

7.

S. Borri, P. Cancio, P. De Natale, G. Giusfredi, D. Mazzotti, and F. Tamassia, “Power-boosted difference-frequency source for high-resolution infrared spectroscopy,” Appl. Phys. B 76, 473–477 (2003). [CrossRef]

8.

D. Mazzotti, S. Borri, P. Cancio, G. Giusfredi, and P. De Natale, “Low-power Lamb-dip spectroscopy of very weak CO2 transitions around 4.25 µm,” Opt. Lett. 27, 1256–1258 (2002). [CrossRef]

9.

D. Mazzotti, P. Cancio, A. Castrillo, I. Galli, G. Giusfredi, and P. De Natale, “A comb-referenced difference-frequency spectrometer for cavity ring-down spectroscopy in the 4.5-µm region,” J. Opt. A 8, S490–S493 (2006). [CrossRef]

10.

D. Mazzotti, P. Cancio, G. Giusfredi, P. De Natale, and M. Prevedelli, “Frequency-comb-based absolute frequency measurements in the mid-IR with a difference-frequency spectrometer,” Opt. Lett. 30, 997–999 (2005). [CrossRef] [PubMed]

11.

E. V. Kovalchuk, T. Schuldt, and A. Peters, “Combination of a continuous-wave optical parametric oscillator and a femtosecond frequency comb for optical frequency metrology,” Opt. Lett. 30, 3141–3143 (2005). [CrossRef] [PubMed]

12.

P. Maddaloni, P. Malara, G. Gagliardi, and P. De Natale, “Mid-infrared fibre-based optical comb,” New J. Phys. 8, 262,1–8 (2006). [CrossRef]

13.

F. Adler, K. Cossel, M. J. Thorpe, I. Hart, M. E. Fermann, and J. Ye “Phase-stabilized, 1.5 W frequency comb at 2.84.8 µm,” Opt. Lett. 34, 1330–1332 (2009). [CrossRef] [PubMed]

14.

J. A. Armstrong, N. Bloembergen, J. Ducuing, and P. S. Pershan, “Interactions between light waves in a nonlinear dielectric,” Phys. Rev. 127, 1918–1939 (1962). [CrossRef]

15.

W. K. Burns, W. McElhanon, and L. Goldberg, “Second harmonic generation in field poled, quasi-phase-matched, bulk LiNbO3,” IEEE Photon. Technol. Lett. 6, 252–254 (1994). [CrossRef]

16.

P. Maddaloni, G. Gagliardi, P. Malara, and P. De Natale, “A 3.5-mW continuous-wave difference-frequency source around 3 µm for sub-Doppler molecular spectroscopy,” Appl. Phys. B 80, 141–145 (2005). [CrossRef]

17.

J. Faist, F. Capasso, D. L. Sivco, C. Sirtori, A. L. Hutchinson, and A. Y. Cho, “Quantum cascade laser,” Science 264, 553–556 (1994). [CrossRef] [PubMed]

18.

R. Maulini, A. Mohan, M. Giovannini, J. Faist, and E. Gini, “External cavity quantum-cascade laser tunable from 8.2 to 10.4 µm using a gain element with a heterogeneous cascade,” Appl. Phys. Lett. 88, 201113,1–3 (2006). [CrossRef]

19.

T. L. Myers, R. M. Williams, M. S. Taubman, C. Gmachl, F. Capasso, D. L. Sivco, J. N. Baillargeon, and A. Y. Cho, “Free-running frequency stability of mid-infrared quantum cascade lasers,” Opt. Lett. 27, 170–172 (2002). [CrossRef]

20.

V. S. Letokhov, “On difference of energy levels of left and right molecules due to weak interactions,” Phys. Lett. A 53, 275–276 (1975). [CrossRef]

21.

C. Daussy, T. Marrel, A. Amy-Klein, C. T. Nguyen, C. J. Bordé, and C. Chardonnet, “Limit on the parity non-conserving energy difference between the enantiomers of a chiral molecule by laser spectroscopy,” Phys. Rev. Lett. 83, 1554–1557 (1999). [CrossRef]

22.

F. Faglioni and P. Lazzeretti, “Parity-violation effect on vibrational spectra,” Phys. Rev. A 67, 032101,1–4 (2003). [CrossRef]

23.

O. W. Greenberg, “Particles with small violations of Fermi or Bose statistics,” Phys. Rev. D 43, 4111–4120 (1991). [CrossRef]

24.

G. Modugno and M. Modugno, “Testing the symmetrization postulate on molecules with three identical nuclei,” Phys. Rev. A 62, 022115,1–8 (2000). [CrossRef]

25.

D. Mazzotti, P. Cancio, G. Giusfredi, M. Inguscio, and P. De Natale, “Search for exchange-antisymmetric states for spin-0 particles at the 10-11 level,” Phys. Rev. Lett. 86, 1919–1922 (2001). [CrossRef] [PubMed]

26.

S. Schiller and V. Korobov, “Tests of time independence of the electron and nuclear masses with ultracold molecules,” Phys. Rev. A 71, 032505,1–7 (2005). [CrossRef]

27.

E. Reinhold, R. Buning, U. Hollenstein, A. Ivanchik, P. Petitjean, and W. Ubachs, “Indication of a cosmological variation of the proton-electron mass ratio based on laboratory measurement and reanalysis of H2 spectra,” Phys. Rev. Lett. 96, 151101,1–4 (2006). [CrossRef]

28.

F. Lang, K. Winkler, C. Strauss, R. Grimm, and J. H. Denschlag, “Ultracold triplet molecules in the rovibrational ground state,” Phys. Rev. Lett. 101, 133005,1–4 (2008). [CrossRef]

29.

H. R. Telle, B. Lipphardt, and J. Stenger, “Kerr-lens mode-locked lasers as transfer oscillators for optical frequency measurements,” Appl. Phys. B 74, 1–6 (2002). [CrossRef]

30.

R. W. P. Drever, J. L. Hall, F. V. Kowalski, J. Hough, G. M. Ford, A. J. Munley, and H. Ward, “Laser phase and frequency stabilization using an optical resonator,” Appl. Phys. B 31, 97–105 (1983). [CrossRef]

31.

B. Dahmani, L. Hollberg, and R. Drullinger, “Frequency stabilization of semiconductor lasers by resonant optical feedback,” Opt. Lett. 12, 876–878 (1987). [CrossRef] [PubMed]

32.

A. Yariv, Quantum electronics, 3rd ed. (Wiley, 1988).

33.

D. Romanini, A. A. Kachanov, N. Sadeghi, and F. Stoeckel, “CW cavity ring down spectroscopy,” Chem. Phys. Lett. 264, 316–322 (1997). [CrossRef]

34.

J. Ye, L.-S. Ma, and J. L. Hall, “Ultrasensitive detections in atomic and molecular physics: demonstration in molecular overtone spectroscopy,” J. Opt. Soc. Am. B 15, 6–15 (1998). [CrossRef]

OCIS Codes
(140.3070) Lasers and laser optics : Infrared and far-infrared lasers
(230.5750) Optical devices : Resonators
(300.6390) Spectroscopy : Spectroscopy, molecular
(190.4223) Nonlinear optics : Nonlinear wave mixing

ToC Category:
Lasers and Laser Optics

History
Original Manuscript: March 26, 2009
Revised Manuscript: April 30, 2009
Manuscript Accepted: May 1, 2009
Published: May 22, 2009

Citation
I. Galli, S. Bartalini, P. Cancio, G. Giusfredi, D. Mazzotti, and P. De Natale, "Ultra-stable, widely tunable and absolutely linked mid-IR coherent source," Opt. Express 17, 9582-9587 (2009)
http://www.opticsinfobase.org/oe/abstract.cfm?URI=oe-17-12-9582


Sort:  Author  |  Year  |  Journal  |  Reset  

References

  1. B. C. Young, F. C. Cruz, W. M. Itano, and J. C. Bergquist, "Visible lasers with subhertz linewidths," Phys. Rev. Lett. 82, 3799-3802 (1999). [CrossRef]
  2. G. Rempe, R. J. Thompson, H. J. Kimble, and R. Lalezari, "Measurement of ultralow losses in an optical interferometer," Opt. Lett. 17, 363-365 (1992). [CrossRef] [PubMed]
  3. S. A. Diddams, D. J. Jones, J. Ye, S. T. Cundiff, J. L. Hall, J. K. Ranka, R. S. Windeler, R. Holzwarth, T. Udem, and T. W. Hansch, "Direct link between microwave and optical frequencies with a 300 THz femtosecond laser comb," Phys. Rev. Lett. 84, 5102-5105 (2000). [CrossRef] [PubMed]
  4. T. Udem, R. Holzwarth, and T. W. Hansch, "Optical frequency metrology," Nature 416, 233-237 (2002). [CrossRef] [PubMed]
  5. T. W. Hansch, "Nobel Lecture: Passion for precision," Rev. Mod. Phys. 78, 1297-1309 (2006). [CrossRef]
  6. J. Nicholson, A. Yablon, P. Westbrook, K. Feder, and M. Yan, "High power, single mode, all-fiber source of femtosecond pulses at 1550 nm and its use in supercontinuum generation," Opt. Express 12, 3025-3034 (2004). [CrossRef] [PubMed]
  7. S. Borri, P. Cancio, P. De Natale, G. Giusfredi, D. Mazzotti, and F. Tamassia, "Power-boosted differencefrequency source for high-resolution infrared spectroscopy," Appl. Phys. B 76, 473-477 (2003). [CrossRef]
  8. D. Mazzotti, S. Borri, P. Cancio, G. Giusfredi, and P. De Natale, "Low-power Lamb-dip spectroscopy of very weak CO2 transitions around 4.25 um," Opt. Lett. 27, 1256-1258 (2002). [CrossRef]
  9. D. Mazzotti, P. Cancio, A. Castrillo, I. Galli, G. Giusfredi, and P. De Natale, "A comb-referenced differencefrequency spectrometer for cavity ring-down spectroscopy in the 4.5-um region," J. Opt. A 8, S490-S493 (2006). [CrossRef]
  10. D. Mazzotti, P. Cancio, G. Giusfredi, P. De Natale, and M. Prevedelli, "Frequency-comb-based absolute frequency measurements in the mid-IR with a difference-frequency spectrometer," Opt. Lett. 30, 997-999 (2005). [CrossRef] [PubMed]
  11. E. V. Kovalchuk, T. Schuldt, and A. Peters, "Combination of a continuous-wave optical parametric oscillator and a femtosecond frequency comb for optical frequency metrology," Opt. Lett. 30, 3141-3143 (2005). [CrossRef] [PubMed]
  12. P. Maddaloni, P. Malara, G. Gagliardi, and P. De Natale, "Mid-infrared fibre-based optical comb," New J. Phys. 8, 262,1-8 (2006). [CrossRef]
  13. F. Adler, K. Cossel, M. J. Thorpe, I. Hart, M. E. Fermann and J. Ye, "Phase-stabilized, 1.5 W frequency comb at 2.84.8 um," Opt. Lett. 34, 1330-1332 (2009). [CrossRef] [PubMed]
  14. J. A. Armstrong, N. Bloembergen, J. Ducuing, and P. S. Pershan, "Interactions between light waves in a nonlinear dielectric," Phys. Rev. 127, 1918-1939 (1962). [CrossRef]
  15. W. K. Burns, W. McElhanon, and L. Goldberg, "Second harmonic generation in field poled, quasi-phase-matched, bulk LiNbO3," IEEE Photon. Technol. Lett. 6, 252-254 (1994). [CrossRef]
  16. P. Maddaloni, G. Gagliardi, P. Malara, and P. De Natale, "A 3.5-mW continuous-wave difference-frequency source around 3 um for sub-Doppler molecular spectroscopy," Appl. Phys. B 80, 141-145 (2005). [CrossRef]
  17. J. Faist, F. Capasso, D. L. Sivco, C. Sirtori, A. L. Hutchinson, and A. Y. Cho, "Quantum cascade laser," Science 264, 553-556 (1994). [CrossRef] [PubMed]
  18. R. Maulini, A. Mohan, M. Giovannini, J. Faist, and E. Gini, "External cavity quantum-cascade laser tunable from 8.2 to 10.4 m using a gain element with a heterogeneous cascade," Appl. Phys. Lett. 88, 201113,1-3 (2006). [CrossRef]
  19. T. L. Myers, R. M. Williams, M. S. Taubman, C. Gmachl, F. Capasso, D. L. Sivco, J. N. Baillargeon, and A. Y. Cho, "Free-running frequency stability of mid-infrared quantum cascade lasers," Opt. Lett. 27, 170-172 (2002). [CrossRef]
  20. V. S. Letokhov, "On difference of energy levels of left and right molecules due to weak interactions," Phys. Lett. A 53, 275-276 (1975). [CrossRef]
  21. C. Daussy, T. Marrel, A. Amy-Klein, C. T. Nguyen, C. J. Bord’e, and C. Chardonnet, "Limit on the parity nonconserving energy difference between the enantiomers of a chiral molecule by laser spectroscopy," Phys. Rev. Lett. 83, 1554-1557 (1999). [CrossRef]
  22. F. Faglioni and P. Lazzeretti, "Parity-violation effect on vibrational spectra," Phys. Rev. A 67, 032101,1-4 (2003). [CrossRef]
  23. O. W. Greenberg, "Particles with small violations of Fermi or Bose statistics," Phys. Rev. D 43, 4111-4120 (1991). [CrossRef]
  24. G. Modugno and M. Modugno, "Testing the symmetrization postulate on molecules with three identical nuclei," Phys. Rev. A 62, 022115,1-8 (2000). [CrossRef]
  25. D. Mazzotti, P. Cancio, G. Giusfredi, M. Inguscio, and P. De Natale, "Search for exchange-antisymmetric states for spin-0 particles at the 10−11 level," Phys. Rev. Lett. 86, 1919-1922 (2001). [CrossRef] [PubMed]
  26. S. Schiller and V. Korobov, "Tests of time independence of the electron and nuclear masses with ultracold molecules," Phys. Rev. A 71, 032505,1-7 (2005). [CrossRef]
  27. E. Reinhold, R. Buning, U. Hollenstein, A. Ivanchik, P. Petitjean, and W. Ubachs, "Indication of a cosmological variation of the proton-electron mass ratio based on laboratory measurement and reanalysis of H2 spectra," Phys. Rev. Lett. 96, 151101,1-4 (2006). [CrossRef]
  28. F. Lang, K. Winkler, C. Strauss, R. Grimm, and J. H. Denschlag, "Ultracold triplet molecules in the rovibrational ground state," Phys. Rev. Lett. 101, 133005,1-4 (2008). [CrossRef]
  29. H. R. Telle, B. Lipphardt, and J. Stenger, "Kerr-lens mode-locked lasers as transfer oscillators for optical frequency measurements," Appl. Phys. B 74, 1-6 (2002). [CrossRef]
  30. R. W. P. Drever, J. L. Hall, F. V. Kowalski, J. Hough, G. M. Ford, A. J. Munley, and H. Ward, "Laser phase and frequency stabilization using an optical resonator," Appl. Phys. B 31, 97-105 (1983). [CrossRef]
  31. B. Dahmani, L. Hollberg, and R. Drullinger, "Frequency stabilization of semiconductor lasers by resonant optical feedback," Opt. Lett. 12, 876-878 (1987). [CrossRef] [PubMed]
  32. A. Yariv, Quantum electronics, 3rd ed. (Wiley, 1988).
  33. D. Romanini, A. A. Kachanov, N. Sadeghi, and F. Stoeckel, "CW cavity ring down spectroscopy," Chem. Phys. Lett. 264, 316-322 (1997). [CrossRef]
  34. J. Ye, L.-S. Ma, and J. L. Hall, "Ultrasensitive detections in atomic and molecular physics: demonstration in molecular overtone spectroscopy," J. Opt. Soc. Am. B 15, 6-15 (1998). [CrossRef]

Cited By

Alert me when this paper is cited

OSA is able to provide readers links to articles that cite this paper by participating in CrossRef's Cited-By Linking service. CrossRef includes content from more than 3000 publishers and societies. In addition to listing OSA journal articles that cite this paper, citing articles from other participating publishers will also be listed.

Figures

Fig. 1. Fig. 2.
 

« Previous Article  |  Next Article »

OSA is a member of CrossRef.

CrossCheck Deposited