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Optics Express

Optics Express

  • Editor: C. Martijn de Sterke
  • Vol. 15, Iss. 19 — Sep. 17, 2007
  • pp: 12161–12166
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Self referenced Yb-fiber-laser frequency comb using a dispersion micromanaged tapered holey fiber

Parama Pal, Wayne H. Knox, Ingmar Hartl, and Martin E. Fermann  »View Author Affiliations


Optics Express, Vol. 15, Issue 19, pp. 12161-12166 (2007)
http://dx.doi.org/10.1364/OE.15.012161


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Abstract

We demonstrate a fully stabilized frequency comb in the 1µm spectral region based on an Yb-fiber oscillator and a cladding pumped chirped pulse Yb-fiber amplifier whose output is spectrally broadened in a dispersion micromanaged holey fiber. The dispersion micromanaged fiber is used to generate efficient, low noise spectral components at 523nm which are heterodyned with the second harmonic of the amplifier output for standard f-to-2f self-referenced carrier envelope offset frequency detection. For comb stabilization we phase-lock this offset frequency and the oscillator repetition frequency simultaneously to an RF reference by feedback controlling the oscillator pump diode current and the driving voltage of an intracavity piezo-electric fiber stretcher respectively.

© 2007 Optical Society of America

1. Introduction

The integration of microstructured fibers with femtosecond laser systems have led to tremendous advances in the field of optical frequency metrology [1

1. D. J. Jones, S. A. Diddams, J. K. Ranka, A. Stentz, R. S. Windeler, J. L. Hall, and S. T. Cundiff, “Carrierenvelope phase control of femtosecond mode-locked lasers and direct optical frequency synthesis,” Science 288, 635–639 (2000) [CrossRef] [PubMed]

3

3. Jun Ye and Steven T. Cundiff eds., Femtosecond Optical Frequency Comb Technology,: Principle, Operation and Application (Springer New York, NY2005)

] initiated by the first demonstration of a self-referenced frequency comb with a Ti:Sapphire based laser system in 2000 [1

1. D. J. Jones, S. A. Diddams, J. K. Ranka, A. Stentz, R. S. Windeler, J. L. Hall, and S. T. Cundiff, “Carrierenvelope phase control of femtosecond mode-locked lasers and direct optical frequency synthesis,” Science 288, 635–639 (2000) [CrossRef] [PubMed]

]. However, Ti:Sapphire systems suffer when it comes to portability as they require frequent re-adjustments, are not very compact, and involve considerable expense owing to their large pump requirements. After its first demonstration by Washburn et al. [4

4. B. R. Washburn, S. A. Diddams, N. R. Newbury, J. W. Nicholson, M. F. Yan, and C. G. Jorgensen, “Phase-locked, erbium-fiber-laser-based frequency comb in the near infrared,” Opt. Lett. 29, 250–252. (2004). [CrossRef] [PubMed]

], self-referenced Er-fiber laser frequency combs have emerged as relatively inexpensive, more compact counterparts, which offer the added advantages of low power consumption, longterm operation and compatibility with existing optical fiber-based technology [4

4. B. R. Washburn, S. A. Diddams, N. R. Newbury, J. W. Nicholson, M. F. Yan, and C. G. Jorgensen, “Phase-locked, erbium-fiber-laser-based frequency comb in the near infrared,” Opt. Lett. 29, 250–252. (2004). [CrossRef] [PubMed]

7

7. P. Kubina, P. Adel, F. Adler, G. Grosche, T. W. Hänsch, R. Holzwarth, A. Leitenstorfer, B. Lipphardt, and H. Schnatz, “Long term comparison of two fiber based frequency comb systems,” Opt. Express 13, 904–909 (2005). [CrossRef] [PubMed]

]. Recently it has been shown that fiber laser frequency combs can provide both excellent long term stability with demonstrated relative Allan standard deviations of 2·10-17 [8

8. H. Schnatz, B. Lipphardt, and G. Grosche, “Frequency Metrology using Fiber-Based fs-Frequency Combs,” in Conference on Lasers and Electro-Optics (Optical Society of America, Long Beach, Ca, 2006), paper CTuH1.

] and excellent short term stability indicated by sub-Hertz relative linewidths and timing jitter of the order of 1fs [9

9. W. C. Swann, J. J. McFerran, I. Coddington, N. R. Newbury, I. Hartl, M. E. Fermann, P. S. Westbrook, J. W. Nicholson, K. S. Feder, C. Langrock, and M. M. Fejer, “Fiber-laser frequency combs with subhertz relative linewidths,” Opt. Lett. 31, 3046–3048 (2006) [CrossRef] [PubMed]

]. Fiber laser frequency combs are therefore suitable tools for highly demanding applications such as optical frequency synthesis, optical clocks and low phase noise RF generation.

In the last few years, there has been increasing focus on several emerging optical standards such as Hg+, Al+ single ions and neutral Yb optical lattice, which provide narrow natural linewidth optical transitions (at 281.5nm, 267nm and 578.4nm respectively) suitable for optical clock applications [10

10. S. A. Diddams, J. C. Bergquist, S. R. Jefferts, and C. W. Oates, “Standards of time and frequency at the outset of the 21st century,” Science 306, 1318–1324. (2004). [CrossRef] [PubMed]

]. All those transitions have sub-harmonics in the spectral region around 1µm (1.126µm, 1.068µm, and 1.157µm respectively) allowing narrow linewidth Yb-fiber laser technology to be used as probe (“clock”) lasers [10

10. S. A. Diddams, J. C. Bergquist, S. R. Jefferts, and C. W. Oates, “Standards of time and frequency at the outset of the 21st century,” Science 306, 1318–1324. (2004). [CrossRef] [PubMed]

]. For the transfer of the optical clock signal within the optical spectral region or to generate an RF clock output, a frequency comb covering the spectral region around 1µm is required and Yb femtosecond laser frequency combs immediately come to mind. Here Yb-fiber laser techology is particularly attractive since it allows the construction of ultra-compact femtosecond oscillators [11

11. I. Hartl, G. Imeshev, L. Dong, G. C. Cho, and M. E. Fermann, “Ultra-compact dispersion compensated femtosecond fiber oscillators and amplifiers,” CLEO (2004), Paper CThG1

] and very efficient, power scalable amplifiers, using the concepts of cladding pumping and chirped pulse amplification [12

12. F. Röser, J. Rothhard, B. Ortac, A. Liem, O. Schmidt, T. Schreiber, J. Limpert, and A. Tünnermann, “131 W 220 fs fiber laser system,” Opt. Lett. 30, 2754 (2005). [CrossRef] [PubMed]

]. However it remains to be shown that those power scaling concepts can be applied without introducing prohibitively large amounts of phase noise, for example, caused by AM-PM conversion in fiber amplifiers.

2. Setup of the experiment

Fig. 1. (a) Experimental set-up. SA: saturable absorber; PZT: piezo actuator; FBG: fiber-Bragg grating; ISO: isolator; PBS: polarizing beam splitter; DMM PCF: dispersion micromanaged photonic crystal fiber; LBO: Lithium triborate; BS: beam-splitter. (b) Autocorrelation measurement of the compressed laser output. For comparison a 117fs FWHM sech2 function is shown.
Fig. 2. (a) Dispersion profiles for the dispersion micromanaged holey fiber’s (DMM HF) initial and final core diameters of 3.3µm and 2.7µm respectively. (b) Spectrum generated by launching ~7 nJ, 130fs pulses into the 18mm long DMM HF. For qualitative comparison a spectrum generated in a 25 mm non-tapered HF as well as the launched laser spectrum is shown.

In order to stabilize the second degree of freedom of the comb, an intermode beat signal at the 28th harmonic of the repetition frequency around 2.55 GHz was phase-locked to a second stable RF synthesizer using a double-balanced mixer as a phase detector and the intracavity fiber stretcher as feedback control element.

3. Results and conclusions

Fig. 3. a) Free running beat signal. b) Mixing product of f CEO and f rep at 125 MHz (phase locked with low gain). c) At higher gain phase locked operation a coherent peak (instrument limited bandwidth) as well as 60Hz pick-off can be observed.
Fig 4. Frequency counter measurement of f CEO (a) and f rep (b). The low frequency oscillatory noise is correlated and might be related to cross talk or various environmental noise sources.

The oscillations on the traces shown in Fig. 3 as well as the 60 Hz sidebands of the phase locked f CEO signal in Fig 3c) are possible caused by imperfections in the locking electronics as well as mechanical vibrations and could be removed by improvements in locking electronics and mechanical isolation. Mechanical drift of the free space fiber coupling to the DMM device required occasional re-alignment, limiting the unattended operation of the fully stabilized system to about 30 minutes.

In conclusion, we have experimentally demonstrated for the first time to our knowledge, a fully phase locked frequency comb centered at the 1 µm spectral region, using a Yb-fiber based laser system which is spectrally broadened by a DMM device. Furthermore we proved that carrier-envelope offset phase control is compatible with the power scalable cladding pumped chirped pulse amplification scheme. This will allow scaling of the average output power of fiber frequency comb lasers well beyond the few-watt limit of bulk Ti:Sapphire oscillator based comb systems. The concept of dispersion micromanagement has been integrated for the first time with a standard self-referencing scheme for self-referenced CEO phase slip detection. We expect that based on Yb-fiber technology frequency combs with GHz repetition rates at improved long-term stability with average powers of more than 10W can be realized. High power Yb-frequency combs will be an important tool for future frequency comb technology in the vacuum ultraviolet (VUV) and extreme ultraviolet (XUV) spectral regions using high harmonic generation within a passive enhancement cavity [25

25. R. Jason Jones, Kevin D. Moll, Michael J. Thorpe, and Jun Ye, “Phase-Coherent Frequency Combs in the Vacuum Ultraviolet via High-Harmonic generation inside a Femtosecond Enhancement Cavity,” Phys. Rev. Lett. 94, 193201 (2005). [CrossRef] [PubMed]

,26

26. Christoph Gohle, Thomas Udem, Maximilian Herrmann, Jens Rauschenberger, Ronald Holzwarth, Hans A. Schuessler, Ferenc Krausz, and Theodor W. Hänsch, “A frequency comb in the extreme ultraviolet,” Nature 436, 234–237 (2005). [CrossRef] [PubMed]

].

References and links

1.

D. J. Jones, S. A. Diddams, J. K. Ranka, A. Stentz, R. S. Windeler, J. L. Hall, and S. T. Cundiff, “Carrierenvelope phase control of femtosecond mode-locked lasers and direct optical frequency synthesis,” Science 288, 635–639 (2000) [CrossRef] [PubMed]

2.

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

3.

Jun Ye and Steven T. Cundiff eds., Femtosecond Optical Frequency Comb Technology,: Principle, Operation and Application (Springer New York, NY2005)

4.

B. R. Washburn, S. A. Diddams, N. R. Newbury, J. W. Nicholson, M. F. Yan, and C. G. Jorgensen, “Phase-locked, erbium-fiber-laser-based frequency comb in the near infrared,” Opt. Lett. 29, 250–252. (2004). [CrossRef] [PubMed]

5.

T. R. Schibli, K. Minoshima, F.-L. Hong, H. Inaba, A. Onae, H. Matsumoto, I. Hartl, and M. E. Fermann, “Frequency metrology with a turnkey all-fiber system,” Opt. Lett. 29, 2467–2469 (2004). [CrossRef] [PubMed]

6.

Holger Hundertmark, Dieter Wandt, Carsten Fallnich, Nils Haverkamp, and Harald R. Telle, “Phase-locked carrier-envelope-offset frequency at 1560 nm,” Opt. Express 12, 770–775 (2004) [CrossRef] [PubMed]

7.

P. Kubina, P. Adel, F. Adler, G. Grosche, T. W. Hänsch, R. Holzwarth, A. Leitenstorfer, B. Lipphardt, and H. Schnatz, “Long term comparison of two fiber based frequency comb systems,” Opt. Express 13, 904–909 (2005). [CrossRef] [PubMed]

8.

H. Schnatz, B. Lipphardt, and G. Grosche, “Frequency Metrology using Fiber-Based fs-Frequency Combs,” in Conference on Lasers and Electro-Optics (Optical Society of America, Long Beach, Ca, 2006), paper CTuH1.

9.

W. C. Swann, J. J. McFerran, I. Coddington, N. R. Newbury, I. Hartl, M. E. Fermann, P. S. Westbrook, J. W. Nicholson, K. S. Feder, C. Langrock, and M. M. Fejer, “Fiber-laser frequency combs with subhertz relative linewidths,” Opt. Lett. 31, 3046–3048 (2006) [CrossRef] [PubMed]

10.

S. A. Diddams, J. C. Bergquist, S. R. Jefferts, and C. W. Oates, “Standards of time and frequency at the outset of the 21st century,” Science 306, 1318–1324. (2004). [CrossRef] [PubMed]

11.

I. Hartl, G. Imeshev, L. Dong, G. C. Cho, and M. E. Fermann, “Ultra-compact dispersion compensated femtosecond fiber oscillators and amplifiers,” CLEO (2004), Paper CThG1

12.

F. Röser, J. Rothhard, B. Ortac, A. Liem, O. Schmidt, T. Schreiber, J. Limpert, and A. Tünnermann, “131 W 220 fs fiber laser system,” Opt. Lett. 30, 2754 (2005). [CrossRef] [PubMed]

13.

H. R. Telle, G. Steinmeyer, A. E. Dunlop, J. Stenger, D. H. Sutter, and U. Keller, “Carrier-envelope offset phase control: A novel concept for absolute optical frequency measurement and ultrashort pulse generation,” Appl. Phys. B 69, 327–332 (1999) [CrossRef]

14.

I. Hartl, M. E. Fermann, C. Langrock, M. M. Fejer, J. W. Nicholson, and D. J. DiGiovanni,“Integrated Fiber-Frequency Comb Using a PPLN Waveguide for Spectral Broadening and CEO Phase Detection,” in Conference on Lasers and Electro-Optics(Optical Society of America, 2006), paper CtuH5.

15.

F. Lu and W. H. Knox, “Generation, characterization, and application of broadband coherent, femtosecond visible pulses in dispersion micromanaged holey fibers,” J. Opt. Soc. Am. B , 23, 1221–1227 (2006) [CrossRef]

16.

Yujun Deng, Fei Lu, and Wayne H. Knox, “Fiber-laser-based difference frequency generation scheme for carrier-envelope-offset phase stabilization applications,” Opt. Express 13, 4589–4593 (2005) [CrossRef] [PubMed]

17.

A. V. Husakou and J. Herrmann, “Supercontinuum Generation of Higher-Order Solitons by Fission in Photonic Crystal Fibers,” Phys. Rev. Lett. 87, 203901 (2001) [CrossRef] [PubMed]

18.

K. L. Corwin, N. R. Newbury, J. M. Dudley, S. Coen, S. A. Diddams, B. R. Washburn, K. Weber, and R. S. Windeler,“Fundamental amplitude noise limitations to supercontinuum spectra generated in a microstructured fiber,” Appl. Phys B 77, 269–277 (2003) [CrossRef]

19.

John M. Dudley, Goery Genty, and Stephane Coen,” Supercontinuum generation in photonic crystal fiber” Rev. Mod. Phys. 78, 1135 (2006) [CrossRef]

20.

Tara M. Fortier, Jun Ye, Steven T. Cundiff, and Robert S. Windeler, “Nonlinear phase noise generated in air-silica microstructure fiber and its effect on carier-envelope phase,” Opt. Lett 27, 445–447 (2002) [CrossRef]

21.

I. Hartl, M. E. Fermann, T. R. Schibli, D. D. Hudson, M. J. Thorpe, R. J. Jones, and J. Ye, “Passive cavity enhancement of a femtosecond fiber chirped pulse amplification system to 204W average power,” Advanced Solid State Photonics (2007), Paper WA4

22.

G. P. Agrawal, Nonlinear Fiber Optics (Academic Press, San Diego, 2001)

23.

N. R. Newbury and B. R. Washburn, “Theory of the Frequency Comb Output From a Femtosecond Fiber Laser,” IEEE J. Quantum Electron. 41, 1388–1402 (2005). [CrossRef]

24.

N. R. Newbury and W. C. Swann, “Low-noise fiber-laser frequency combs (Invited),” J. Opt. Soc. Am. B 24, 1756–1770 (2007). [CrossRef]

25.

R. Jason Jones, Kevin D. Moll, Michael J. Thorpe, and Jun Ye, “Phase-Coherent Frequency Combs in the Vacuum Ultraviolet via High-Harmonic generation inside a Femtosecond Enhancement Cavity,” Phys. Rev. Lett. 94, 193201 (2005). [CrossRef] [PubMed]

26.

Christoph Gohle, Thomas Udem, Maximilian Herrmann, Jens Rauschenberger, Ronald Holzwarth, Hans A. Schuessler, Ferenc Krausz, and Theodor W. Hänsch, “A frequency comb in the extreme ultraviolet,” Nature 436, 234–237 (2005). [CrossRef] [PubMed]

OCIS Codes
(140.3510) Lasers and laser optics : Lasers, fiber
(190.4370) Nonlinear optics : Nonlinear optics, fibers
(320.7090) Ultrafast optics : Ultrafast lasers

ToC Category:
Lasers and Laser Optics

History
Original Manuscript: July 6, 2007
Revised Manuscript: September 6, 2007
Manuscript Accepted: September 6, 2007
Published: September 10, 2007

Citation
Parama Pal, Wayne H. Knox, Ingmar Hartl, and Martin E. Fermann, "Self referenced Yb-fiber-laser frequency comb using a dispersion micromanaged tapered holey fiber," Opt. Express 15, 12161-12166 (2007)
http://www.opticsinfobase.org/oe/abstract.cfm?URI=oe-15-19-12161


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References

  1. D. J. Jones, S. A. Diddams, J. K. Ranka, A. Stentz, R. S. Windeler, J. L. Hall, and S. T. Cundiff, "Carrier-envelope phase control of femtosecond mode-locked lasers and direct optical frequency synthesis," Science 288, 635-639 (2000) [CrossRef] [PubMed]
  2. Th. Udem, R. Holzwarth, and T. W. Hänsch, "Optical Frequency Metrology," Nature 416, 233-237 (2002) [CrossRef] [PubMed]
  3. Jun Ye and Steven T. Cundiff eds., Femtosecond Optical Frequency Comb Technology: Principle, Operation and Application (Springer New York, NY 2005)
  4. B. R. Washburn, S. A. Diddams, N. R. Newbury, J. W. Nicholson, M. F. Yan, and C. G. Jorgensen, "Phase-locked, erbium-fiber-laser-based frequency comb in the near infrared," Opt. Lett. 29,250-252. (2004). [CrossRef] [PubMed]
  5. T. R. Schibli, K. Minoshima, F.-L. Hong, H. Inaba, A. Onae, H. Matsumoto, I. Hartl, and M. E. Fermann, "Frequency metrology with a turnkey all-fiber system," Opt. Lett. 29,2467-2469 (2004). [CrossRef] [PubMed]
  6. H. Hundertmark, D. Wandt, C. Fallnich, N. Haverkamp, and H. R. Telle, "Phase-locked carrier-envelope-offset frequency at 1560 nm," Opt. Express 12,770-775 (2004) [CrossRef] [PubMed]
  7. P. Kubina, P. Adel, F. Adler, G. Grosche, T. W. Hänsch, R. Holzwarth, A. Leitenstorfer, B. Lipphardt, and H. Schnatz, "Long term comparison of two fiber based frequency comb systems," Opt. Express 13, 904-909 (2005). [CrossRef] [PubMed]
  8. H. Schnatz, B. Lipphardt, and G. Grosche, "Frequency Metrology using Fiber-Based fs-Frequency Combs," in Conference on Lasers and Electro-Optics (Optical Society of America, Long Beach, Ca, 2006), paper CTuH1.
  9. W. C. Swann, J. J. McFerran, I. Coddington, N. R. Newbury, I. Hartl, M. E. Fermann, P. S. Westbrook, J. W. Nicholson, K. S. Feder, C. Langrock, M. M. Fejer, "Fiber-laser frequency combs with subhertz relative linewidths," Opt. Lett. 31, 3046-3048 (2006) [CrossRef] [PubMed]
  10. S. A. Diddams, J. C. Bergquist, S. R. Jefferts, and C. W. Oates, "Standards of time and frequency at the outset of the 21st century," Science 306,1318-1324. (2004). [CrossRef] [PubMed]
  11. I. Hartl, G. Imeshev, L. Dong, G. C. Cho and M. E. Fermann, "Ultra-compact dispersion compensated femtosecond fiber oscillators and amplifiers," CLEO (2004), Paper CThG1
  12. F. Röser, J. Rothhard, B. Ortac, A. Liem, O. Schmidt, T. Schreiber, J. Limpert, and A. Tünnermann, "131 W 220 fs fiber laser system," Opt. Lett. 30,2754 (2005). [CrossRef] [PubMed]
  13. H. R. Telle, G. Steinmeyer, A. E. Dunlop, J. Stenger, D. H. Sutter, and U. Keller, "Carrier-envelope offset phase control: A novel concept for absolute optical frequency measurement and ultrashort pulse generation," Appl. Phys. B 69, 327-332 (1999) [CrossRef]
  14. I. Hartl, M. E. Fermann, C. Langrock, M. M. Fejer, J. W. Nicholson, and D. J. DiGiovanni, "Integrated Fiber-Frequency Comb Using a PPLN Waveguide for Spectral Broadening and CEO Phase Detection," in Conference on Lasers and Electro-Optics(Optical Society of America, 2006), paper CtuH5.
  15. F. Lu, and W. H. Knox, "Generation, characterization, and application of broadband coherent, femtosecond visible pulses in dispersion micromanaged holey fibers," J. Opt. Soc. Am. B,  23,1221-1227 (2006) [CrossRef]
  16. Y. Deng, F. Lu, and W. H. Knox, "Fiber-laser-based difference frequency generation scheme for carrier-envelope-offset phase stabilization applications," Opt. Express 13, 4589-4593 (2005) [CrossRef] [PubMed]
  17. A. V. Husakou and J. Herrmann, "Supercontinuum Generation of Higher-Order Solitons by Fission in Photonic Crystal Fibers," Phys. Rev. Lett. 87, 203901 (2001) [CrossRef] [PubMed]
  18. K. L. Corwin, N. R. Newbury, J. M. Dudley, S. Coen, S. A. Diddams, B. R. Washburn, K. Weber, and R. S. Windeler,"Fundamental amplitude noise limitations to supercontinuum spectra generated in a microstructured fiber," Appl. Phys B 77, 269-277 (2003) [CrossRef]
  19. J. M. Dudley, G. Genty, and S. Coen," Supercontinuum generation in photonic crystal fiber" Rev. Mod. Phys. 78, 1135 (2006) [CrossRef]
  20. T. M. Fortier, J. Ye, S. T. Cundiff, and R. S. Windeler, "Nonlinear phase noise generated in air-silica microstructure fiber and its effect on carier-envelope phase," Opt. Lett 27, 445-447 (2002) [CrossRef]
  21. I. Hartl, M. E. Fermann, T. R. Schibli, D. D. Hudson, M. J. Thorpe, R. J. Jones, and J. Ye, "Passive cavity enhancement of a femtosecond fiber chirped pulse amplification system to 204W average power," Advanced Solid State Photonics (2007), Paper WA4.
  22. G. P. Agrawal, Nonlinear Fiber Optics (Academic Press, San Diego, 2001)
  23. N. R. Newbury, and B. R. Washburn, "Theory of the Frequency Comb Output From a Femtosecond Fiber Laser," IEEE J. Quantum Electron. 41, 1388-1402 (2005). [CrossRef]
  24. N. R. Newbury and W. C. Swann, "Low-noise fiber-laser frequency combs (Invited)," J. Opt. Soc. Am. B 24, 1756-1770 (2007). [CrossRef]
  25. R. Jason Jones, KevinD. Moll, Michael J. Thorpe, and Jun Ye, "Phase-Coherent Frequency Combs in the Vacuum Ultraviolet via High-Harmonic generation inside a Femtosecond Enhancement Cavity," Phys. Rev. Lett. 94, 193201 (2005). [CrossRef] [PubMed]
  26. C. Gohle, T. Udem, M. Herrmann, J. Rauschenberger, R. Holzwarth, H. A. Schuessler, F. Krausz, and T. W. Hänsch, "A frequency comb in the extreme ultraviolet," Nature 436, 234-237 (2005). [CrossRef] [PubMed]

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