High-Speed Mid-Infrared Frequency Modulation Spectroscopy Based on Quantum Cascade Laser

We demonstrated a high-speed mid-infrared frequency modulation spectroscopy scheme based on a distributed-feedback quantum Cascade laser for the application in trace gas sensing by means of all-optical frequency modulation. With this method, the modulation frequency spectrum of a gas sample can be obtained within the mid-infrared pulse duration of ~200 ns. A frequency modulation of the middle infrared lasing optical frequency was achieved in quantum Cascade laser with a modulation frequency of 200 MHz by illuminating with a 1550-nm near-infrared laser. For CO gas, with 2-mW near-infrared illumination, the noise-equivalent sensitivity of the frequency modulation spectroscopy was estimated to be 0.12 ppmv for an absorption length of 6.1 m, indicating an improvement by a factor of 7 compared with Voigt-fitted direct absorption spectroscopy (0.84 ppmv). The frequency modulation signal was found to be proportional to the incident near-infrared power, and therefore, the noise-equivalent sensitivity is expected to be further improved by increasing the near-infrared illumination power. This high-speed frequency modulation spectroscopy based on the distributed-feedback quantum Cascade laser has promising applications in high-speed and high-sensitivity gas sensing.

[1]  John Tulip,et al.  Wavelength modulation spectroscopy with a pulsed quantum cascade laser for the sensitive detection of acrylonitrile , 2011 .

[2]  S. Borri,et al.  Frequency modulation spectroscopy by means of quantum-cascade lasers , 2006 .

[3]  Nicolas Godbout,et al.  Large nonlinear Kerr effect in graphene , 2012, 1203.5527.

[4]  Gerard Wysocki,et al.  High frequency modulation capabilities and quasi single-sideband emission from a quantum cascade laser. , 2014, Optics express.

[5]  Gerard Wysocki,et al.  Pulsed quantum-cascade laser-based sensor for trace-gas detection of carbonyl sulfide. , 2004, Applied optics.

[6]  David D. Nelson,et al.  Recent progress in laser-based trace gas instruments: performance and noise analysis , 2015 .

[7]  Gang Chen,et al.  Non-resonant optical modulation of quantum cascade laser and its application potential in infrared spectroscopy , 2014, Photonics West - Optoelectronic Materials and Devices.

[8]  E. J. Moyer,et al.  Design considerations in high-sensitivity off-axis integrated cavity output spectroscopy , 2008 .

[9]  H. Hübers,et al.  Frequency modulation spectroscopy with a THz quantum-cascade laser. , 2013, Optics express.

[10]  B. Hinkov,et al.  Time-resolved spectral characteristics of external-cavity quantum cascade lasers and their application to stand-off detection of explosives , 2010 .

[11]  Nicolas Godbout,et al.  Z-scan measurement of the nonlinear refractive index of graphene. , 2012, Optics letters.

[12]  Fengqi Liu,et al.  High-performance uncooled distributed-feedback quantum cascade laser without lateral regrowth , 2012 .

[13]  Rainer Martini,et al.  High-speed all-optical modulation of a standard quantum cascade laser by front facet illumination , 2009 .

[14]  E. Whittaker,et al.  Theoretical description of frequency modulation and wavelength modulation spectroscopy. , 1994, Applied optics.

[15]  John Tulip,et al.  Sensitive detection of ammonia and ethylene with a pulsed quantum cascade laser using intra and interpulse spectroscopic techniques , 2009 .

[16]  Seong-Wook Park,et al.  Optically induced fast wavelength modulation in a quantum cascade laser , 2010 .

[17]  L. Wang,et al.  Intrapulse quantum cascade laser spectroscopy: pressure induced line broadening and shifting in the ν6 band of formaldehyde , 2012 .

[18]  Grant A. D. Ritchie,et al.  Direct and wavelength modulation spectroscopy using a cw external cavity quantum cascade laser , 2009 .

[19]  E. Normand,et al.  Highly sensitive detection of trace gases using the time-resolved frequency downchirp from pulsed quantum-cascade lasers , 2003 .

[20]  J. Faist,et al.  Quantum Cascade Laser , 1994, Science.

[21]  Ronald K. Hanson,et al.  Wavelength-modulation-spectroscopy for real-time, in situ NO detection in combustion gases with a 5.2 μm quantum-cascade laser , 2012 .