Abstract

A Stark-tuned optically pumped far-infrared CH3OH laser operating at 119 μm has been built. The laser is designed to operate at high power while exhibiting a well-separated Stark doublet. At a pump power of 65 W and an electric field of 1 kV/cm the laser has delivered over 100 mW cw while exhibiting a frequency splitting of 34 MHz. These parameters indicate that this laser would be suitable for use in the present generation of modulated interferometers on large thermonuclear plasma devices. The achieved modulation frequency is more than an order of magnitude higher than could be achieved by using standard techniques.

© 1992 Optical Society of America

Full Article  |  PDF Article

References

  • View by:
  • |
  • |
  • |

  1. S. M. Wolfe, K. J. Button, J. Waldman, D. R. Cohn, “Modulated submillimeter laser interferometer system for plasma density measurements,” Appl. Opt. 15, 2645–2648 (1976).
    [CrossRef] [PubMed]
  2. D. K. Mansfield, H. K. Park, L. C. Johnson, H. M. Anderson, R. Chouinard, V. S. Foote, C. H. Ma, B. J. Clifton, “Multichannel far-infrared laser interferometer for electron density measurements on the tokamak fusion test reactor,” Appl. Opt. 26, 4469–4474 (1987).
    [CrossRef] [PubMed]
  3. G. Bionducci, M. Inguscio, A. Moretti, F. Strumia, “Design of molecular FIR lasers frequency tunable by Stark effect: electric breakdown of CH3OH, CH3F, CH3I and CH3CN,” Infrared Phys. 9, 297–308 (1979).
    [CrossRef]
  4. D. K. Mansfield, E. Horlbeck, C. L. Bennett, R. Chouinard, “Enhanced, high power operation of the 119 μm line of optically pumped CH3OH,” Int. J. Infrared Millimeter Waves 6, 867–876 (1985).
    [CrossRef]
  5. D. T. Hodges, F. B. Foote, R. D. Reel, “Efficient high-power operation of the cw far-infrared waveguide laser,” Appl. Phys. Lett. 29, 662–664 (1976).
    [CrossRef]
  6. H. R. Fetterman, P. E. Tannenwald, B. J. Clifton, C. D. Parker, W. D. Fitzgerald, N. R. Erikson, “Far-IR heterodyne radiometric measurements with quasioptical Schottky diode mixers,” Appl. Phys. Lett. 33, 151–154 (1978).
    [CrossRef]

1987 (1)

1985 (1)

D. K. Mansfield, E. Horlbeck, C. L. Bennett, R. Chouinard, “Enhanced, high power operation of the 119 μm line of optically pumped CH3OH,” Int. J. Infrared Millimeter Waves 6, 867–876 (1985).
[CrossRef]

1979 (1)

G. Bionducci, M. Inguscio, A. Moretti, F. Strumia, “Design of molecular FIR lasers frequency tunable by Stark effect: electric breakdown of CH3OH, CH3F, CH3I and CH3CN,” Infrared Phys. 9, 297–308 (1979).
[CrossRef]

1978 (1)

H. R. Fetterman, P. E. Tannenwald, B. J. Clifton, C. D. Parker, W. D. Fitzgerald, N. R. Erikson, “Far-IR heterodyne radiometric measurements with quasioptical Schottky diode mixers,” Appl. Phys. Lett. 33, 151–154 (1978).
[CrossRef]

1976 (2)

S. M. Wolfe, K. J. Button, J. Waldman, D. R. Cohn, “Modulated submillimeter laser interferometer system for plasma density measurements,” Appl. Opt. 15, 2645–2648 (1976).
[CrossRef] [PubMed]

D. T. Hodges, F. B. Foote, R. D. Reel, “Efficient high-power operation of the cw far-infrared waveguide laser,” Appl. Phys. Lett. 29, 662–664 (1976).
[CrossRef]

Anderson, H. M.

Bennett, C. L.

D. K. Mansfield, E. Horlbeck, C. L. Bennett, R. Chouinard, “Enhanced, high power operation of the 119 μm line of optically pumped CH3OH,” Int. J. Infrared Millimeter Waves 6, 867–876 (1985).
[CrossRef]

Bionducci, G.

G. Bionducci, M. Inguscio, A. Moretti, F. Strumia, “Design of molecular FIR lasers frequency tunable by Stark effect: electric breakdown of CH3OH, CH3F, CH3I and CH3CN,” Infrared Phys. 9, 297–308 (1979).
[CrossRef]

Button, K. J.

Chouinard, R.

D. K. Mansfield, H. K. Park, L. C. Johnson, H. M. Anderson, R. Chouinard, V. S. Foote, C. H. Ma, B. J. Clifton, “Multichannel far-infrared laser interferometer for electron density measurements on the tokamak fusion test reactor,” Appl. Opt. 26, 4469–4474 (1987).
[CrossRef] [PubMed]

D. K. Mansfield, E. Horlbeck, C. L. Bennett, R. Chouinard, “Enhanced, high power operation of the 119 μm line of optically pumped CH3OH,” Int. J. Infrared Millimeter Waves 6, 867–876 (1985).
[CrossRef]

Clifton, B. J.

D. K. Mansfield, H. K. Park, L. C. Johnson, H. M. Anderson, R. Chouinard, V. S. Foote, C. H. Ma, B. J. Clifton, “Multichannel far-infrared laser interferometer for electron density measurements on the tokamak fusion test reactor,” Appl. Opt. 26, 4469–4474 (1987).
[CrossRef] [PubMed]

H. R. Fetterman, P. E. Tannenwald, B. J. Clifton, C. D. Parker, W. D. Fitzgerald, N. R. Erikson, “Far-IR heterodyne radiometric measurements with quasioptical Schottky diode mixers,” Appl. Phys. Lett. 33, 151–154 (1978).
[CrossRef]

Cohn, D. R.

Erikson, N. R.

H. R. Fetterman, P. E. Tannenwald, B. J. Clifton, C. D. Parker, W. D. Fitzgerald, N. R. Erikson, “Far-IR heterodyne radiometric measurements with quasioptical Schottky diode mixers,” Appl. Phys. Lett. 33, 151–154 (1978).
[CrossRef]

Fetterman, H. R.

H. R. Fetterman, P. E. Tannenwald, B. J. Clifton, C. D. Parker, W. D. Fitzgerald, N. R. Erikson, “Far-IR heterodyne radiometric measurements with quasioptical Schottky diode mixers,” Appl. Phys. Lett. 33, 151–154 (1978).
[CrossRef]

Fitzgerald, W. D.

H. R. Fetterman, P. E. Tannenwald, B. J. Clifton, C. D. Parker, W. D. Fitzgerald, N. R. Erikson, “Far-IR heterodyne radiometric measurements with quasioptical Schottky diode mixers,” Appl. Phys. Lett. 33, 151–154 (1978).
[CrossRef]

Foote, F. B.

D. T. Hodges, F. B. Foote, R. D. Reel, “Efficient high-power operation of the cw far-infrared waveguide laser,” Appl. Phys. Lett. 29, 662–664 (1976).
[CrossRef]

Foote, V. S.

Hodges, D. T.

D. T. Hodges, F. B. Foote, R. D. Reel, “Efficient high-power operation of the cw far-infrared waveguide laser,” Appl. Phys. Lett. 29, 662–664 (1976).
[CrossRef]

Horlbeck, E.

D. K. Mansfield, E. Horlbeck, C. L. Bennett, R. Chouinard, “Enhanced, high power operation of the 119 μm line of optically pumped CH3OH,” Int. J. Infrared Millimeter Waves 6, 867–876 (1985).
[CrossRef]

Inguscio, M.

G. Bionducci, M. Inguscio, A. Moretti, F. Strumia, “Design of molecular FIR lasers frequency tunable by Stark effect: electric breakdown of CH3OH, CH3F, CH3I and CH3CN,” Infrared Phys. 9, 297–308 (1979).
[CrossRef]

Johnson, L. C.

Ma, C. H.

Mansfield, D. K.

D. K. Mansfield, H. K. Park, L. C. Johnson, H. M. Anderson, R. Chouinard, V. S. Foote, C. H. Ma, B. J. Clifton, “Multichannel far-infrared laser interferometer for electron density measurements on the tokamak fusion test reactor,” Appl. Opt. 26, 4469–4474 (1987).
[CrossRef] [PubMed]

D. K. Mansfield, E. Horlbeck, C. L. Bennett, R. Chouinard, “Enhanced, high power operation of the 119 μm line of optically pumped CH3OH,” Int. J. Infrared Millimeter Waves 6, 867–876 (1985).
[CrossRef]

Moretti, A.

G. Bionducci, M. Inguscio, A. Moretti, F. Strumia, “Design of molecular FIR lasers frequency tunable by Stark effect: electric breakdown of CH3OH, CH3F, CH3I and CH3CN,” Infrared Phys. 9, 297–308 (1979).
[CrossRef]

Park, H. K.

Parker, C. D.

H. R. Fetterman, P. E. Tannenwald, B. J. Clifton, C. D. Parker, W. D. Fitzgerald, N. R. Erikson, “Far-IR heterodyne radiometric measurements with quasioptical Schottky diode mixers,” Appl. Phys. Lett. 33, 151–154 (1978).
[CrossRef]

Reel, R. D.

D. T. Hodges, F. B. Foote, R. D. Reel, “Efficient high-power operation of the cw far-infrared waveguide laser,” Appl. Phys. Lett. 29, 662–664 (1976).
[CrossRef]

Strumia, F.

G. Bionducci, M. Inguscio, A. Moretti, F. Strumia, “Design of molecular FIR lasers frequency tunable by Stark effect: electric breakdown of CH3OH, CH3F, CH3I and CH3CN,” Infrared Phys. 9, 297–308 (1979).
[CrossRef]

Tannenwald, P. E.

H. R. Fetterman, P. E. Tannenwald, B. J. Clifton, C. D. Parker, W. D. Fitzgerald, N. R. Erikson, “Far-IR heterodyne radiometric measurements with quasioptical Schottky diode mixers,” Appl. Phys. Lett. 33, 151–154 (1978).
[CrossRef]

Waldman, J.

Wolfe, S. M.

Appl. Opt. (2)

Appl. Phys. Lett. (2)

D. T. Hodges, F. B. Foote, R. D. Reel, “Efficient high-power operation of the cw far-infrared waveguide laser,” Appl. Phys. Lett. 29, 662–664 (1976).
[CrossRef]

H. R. Fetterman, P. E. Tannenwald, B. J. Clifton, C. D. Parker, W. D. Fitzgerald, N. R. Erikson, “Far-IR heterodyne radiometric measurements with quasioptical Schottky diode mixers,” Appl. Phys. Lett. 33, 151–154 (1978).
[CrossRef]

Infrared Phys. (1)

G. Bionducci, M. Inguscio, A. Moretti, F. Strumia, “Design of molecular FIR lasers frequency tunable by Stark effect: electric breakdown of CH3OH, CH3F, CH3I and CH3CN,” Infrared Phys. 9, 297–308 (1979).
[CrossRef]

Int. J. Infrared Millimeter Waves (1)

D. K. Mansfield, E. Horlbeck, C. L. Bennett, R. Chouinard, “Enhanced, high power operation of the 119 μm line of optically pumped CH3OH,” Int. J. Infrared Millimeter Waves 6, 867–876 (1985).
[CrossRef]

Cited By

OSA participates in CrossRef's Cited-By Linking service. Citing articles from OSA journals and other participating publishers are listed here.

Alert me when this article is cited.


Figures (5)

Fig. 1
Fig. 1

Cross section of the FIR resonator tube used in this work. Also shown is the orientation of the FIR and pump polarizations.

Fig. 2
Fig. 2

Cavity scan from the 2-m Stark laser with no applied field. The cavity modes shown coupled efficiently into TEM00 free-space modes.

Fig. 3
Fig. 3

Cavity scan from the 2-m Stark laser with the CH3OH pressure lowered to permit the application of an ≈ 1-kV/cm electric field without breakdown. This operating point was chosen as a trade-off between power and doublet splitting. A doublet splitting of ≈ 35 MHz is clearly seen at a power level above 100 mW.

Fig. 4
Fig. 4

Beat spectrum (2 MHz/div) from the unshifted output from a standard FIR laser mixed with the 1-m Stark-shifted laser output. A modulation frequency of ≈ 14 MHz is clearly seen. The component at ≈ 1 MHz is from an unwanted transverse mode in the unshifted laser. A Schottky diode was used as the mixer. The laser configuration associated with the measurement is shown in the inset figure.

Fig. 5
Fig. 5

Optical method of generating the modulation frequency in the present generation of FIR interferometers. Two lasers (A & B) are tuned on opposite sides of a narrow gain curve. This technique is limited by the gain bandwidth to frequences of ~ 1 MHz. (b) In this work, the gain curve is Stark split and the lasers are tuned to the two available peaks. The modulation frequency and long-term stability are thus greatly increased.

Equations (4)

Equations on this page are rendered with MathJax. Learn more.

V ref ( t ) α cos ( Δ ω t ) ,
V scene ( t ) α cos [ Δ ω t + ζ ( t ) ] ,
ζ ( t ) α n ( r , t ) d l ,
ζ ( t ) / t Δ ω .

Metrics