Old Research theme

Molecular spectroscopy with near-infrared semiconductor lasers

Recently optical technology has made remarkable progresses for optical communications, optical disks, laser printers, and so on. For these applications, semiconductor lasers have been also developed in particular those for the near-infrared region. These semiconductor lasers have several advantages over the other lasers as a light source for spectroscopy; compactness, high efficiency, small amplitude noise, and wide tunability. External-cavity semiconductor lasers are particularly useful for high-resolution molecular spectroscopy because of the extremely wide tunability and narrow spectral linewidth.

Sasada group has carried out spectroscopic studies on not only stable molecules such as hydrogen cyanide, acetylene, heavy water, ammonia, and methane but also transient molecules like HN2+ and C3 using DFB semiconductor lasers and laboratory-made external-cavity semiconductor lasers in the 1.55- and 1.66-μm regions.

List of publications

  1. K. Suzumura, C. Ishibashi, and H. Sasada, "Precise frequency-difference measurement between the 1.66-μm transitions of methane," Optics Letter, 22(17), 1356-1358 (1997).
  2. H. Sasada, "Chapter II, Near-infrared molecular spectroscopy and possible frequency references for frequency control of semiconductor lasers," in "Frequency control of semiconductor lasers," edited by M. Ohtsu, John Wiley & Sons, Inc., New York (1996).
  3. 3. H. Sasada, K. Suzumura, and C. Ishibashi, "Coriolis-dependent Stark effect of the 2ν3 band of methane observed by saturated absorption spectroscopy," Journal of Chemical Physics, 105(20), 9027-9034(1996).
  4. K. Suzumura and H. Sasada, "Observation of saturation spectrum of the 2ν3 band of methane," Japanese Journal of Applied Physics, 34(12A), L1620-L1621 (1995).
  5. H. Sasada and Y. Kuba, "Vibrationally induced dipole moment of the ν3=2 state of methane," Journal of Molecular Spectroscopy, 172, 573-575 (1995).
  6. H. Sasada, T. Amano, C. Jarman, and P. F. Bernath, "A new triplet band system of C3: the b3Pg-a3Putransition," Jouranl of Chemical Physics, 94(4), 2401-2407 (1991).
  7. S. Kinugawa and H. Sasada,"Wavenumber measurement of the 1.5-μm band of acetylene by semiconductor laser spectrometer," Japanese Journal of Applied Physics, 29(3), 611-612 (1990).
  8. H. Sasada and T. Amano, "Observation of the 2ν1 band of HN2+ with a 1.57 μm distributed feedback semiconductor laser," Journal of Chemical Physics, 92(4), 2248-2250 (1990).
  9. H. Sasada and K. Yamada, "Calibration lines of HCN in the 1.5-μm region," Applied Optics, 29 (24), 3535-3547 (1990).
  10. T. Ohshima and H. Sasada, "1.5-μm DFB Semiconductor laser spectroscopy of deutrated water," Journal of Molecular Spectroscopy, 136, 250-263 (1989).
  11. H. Sasada, "1.5 μm DFB semiconductor laser spectroscopy of HCN," Journal of Chemical Physics, 88(2), 767-777 (1987).
  12. H. Sasada, "Stark-modulation spectroscopy of NH3 with a 1.23-μm semiconductor laser," Optics Letters, 9(10), 448-450 (1984).