TITLE

Linewidth measurement of free-running, pulsed, distributed feedback quantum cascade lasers

AUTHOR(S)
Beyer, Thomas; Braun, Marcus; Hartwig, Susanne; Lambrecht, Armin
PUB. DATE
May 2004
SOURCE
Journal of Applied Physics;5/1/2004, Vol. 95 Issue 9, p4551
SOURCE TYPE
Academic Journal
DOC. TYPE
Article
ABSTRACT
In gas spectroscopy with distributed feedback quantum cascade lasers (DFB-QCLs), linewidth is an important measurement parameter. However, in standard usage, these lasers are used in pulsed operation, so that the laser linewidth can no longer be assumed to remain constant over the length of the pulse. For the instantaneous measurement of such dynamic linewidths, a suitable measurement technique was still lacking. Frequently, pulse lengths of 5 to 10 ns are used to obtain laser linewidths that will be suitable for gas measurements. In these experiments, standard photoconductive or photovoltaic mid-infrared detectors with bandwidths in the 1 MHz range are employed, so that the linewidth is averaged over the tuning range of the QCL. The linewidth averaging could be reduced by shorter pulses, but for pulses shorter than 5 ns, the Fourier limitation increases the linewidth again. We present a technique to measure the dynamic laser linewidth continuously within a laser pulse of 30 ns to several μs. Due to the use of high-bandwidth detectors working from 2 to 12 μm, laser linewidths can be determined much more accurately than with short pulses. Instantaneous linewidths of DFB-QCLs down to 60 MHz are obtained. This shows that QCLs are well suited for gas measurement in the mid-infrared. © 2004 American Institute of Physics.
ACCESSION #
12855061

 

Related Articles

  • Time variation of the intensity of spectral lines due to a plasma generated under the action of intense infrared laser radiation on a germanium target. Chuchman, M.; Shuaibov, A. // Technical Physics;Apr2008, Vol. 53 Issue 4, p494 

    The time waveforms of the intensity of spectral lines associated with a germanium laser plasma is studied by the emission spectroscopy method. The plasma is generated by irradiating a germanium target by a pulsed-periodic IR radiation from a neodymium laser, and the intensity waveforms are taken...

  • Spectroscopy of the deformed126Ce nucleus. Petrache, C. M.; Lo Bianco, G.; Bizzeti, P. G.; Bizzeti-Sona, A. M.; Bazzacco, D.; Lunardi, S.; Nespolo, M.; de Angelis, G.; Napoli, D. R.; Blasi, N.; Brant, S.; Vretenar, D. // European Physical Journal A -- Hadrons & Nuclei;Mar2003, Vol. 16 Issue 3, p337 

    The even-even nucleus126Ce was studied via in-beam γ-ray spectroscopy using the40Ca +92Mo reaction at 190 MeV. Five bands were observed, one of them being identified for the first time. New connecting transitions were identified between the bands, which lead to new spin assignments. The bands...

  • Strong mid-infrared radiation from self-guided fast electron bunch propagating along a grated target surface in laser-solid interaction. Zhuo, H. B.; Jin, Z.; Yu, M. Y.; Sheng, Z. M.; Xu, H.; Ma, Y. Y.; Yin, Y.; Shao, F. Q.; Zhou, W. M.; Kodama, R. // Physics of Plasmas;Apr2012, Vol. 19 Issue 4, p043108 

    Generation of 1012 W/cm2 Smith-Purcell radiation in the infrared (5-20μm) regime from the interaction of high-density laser-produced MeV electrons is proposed. The electron bunch is produced by impinging an intense ultrashort laser pulse on a metallic target with a grated upper surface....

  • Laser assisted heating of extreme ultraviolet-emitting z-pinch plasmas. Wieneke, Stephan; Brückner, Stephan; Viöl, Wolfgang // Physics of Plasmas;Dec2008, Vol. 15 Issue 12, p122508 

    A low-current and low-compression z-pinch nitrogen plasma is heated up by means of a short laser pulse. Spectra are taken in the extreme ultraviolet spectral range from 11 to 18 nm to estimate the heating effect. Without additional laser heating the initial plasma conditions are ne≈1017...

  • One-dimensional simulations of reversed field pinch discharges. Martines, E.; Spagnolo, S. // Physics of Plasmas;Dec2008, Vol. 15 Issue 12, p122506 

    A simple one-dimensional time-dependent model for simulating the magnetic field profiles in a reversed field pinch (RFP) plasma is presented. The model, which is derived from basic MHD equations with the addition of a phenomenological dynamo electric field, is able, through the tuning of a few...

  • Micron-scale width multislot plasma cathode. Yarmolich, D.; Vekselman, V.; Gurovich, V. Tz.; Gleizer, J. Z.; Felsteiner, J.; Krasik, Ya. E. // Physics of Plasmas;Dec2008, Vol. 15 Issue 12, p123507 

    High-current electron beam (∼1.5 kA, ∼30 A/cm2, ∼200 keV, ∼300 ns) generation in a diode with a micron-scale width multislot cathode is reported. The cathode operation is based on plasma formation inside slots formed by a stack of glass plates interlaid with 25 μm Cu...

  • Intense laser-driven relativistic electron beams in a two-layer target. Zhou, C. T.; He, X. T. // Physics of Plasmas;Dec2008, Vol. 15 Issue 12, p123105 

    An intense short-pulse laser irradiates solid targets to produce relativistic electrons by depositing the light energy at the relativistic critical density. These fast electrons propagating through a coaxial two-layer plasma target can generate tens of million-Gauss interface magnetic fields at...

  • The role of parallel heat transport in the relation between upstream scrape-off layer widths and target heat flux width in H-mode plasmas of the National Spherical Torus Experiment. Ahn, J.-W.; Boedo, J. A.; Maingi, R.; Soukhanovskii, V. // Physics of Plasmas;Dec2008, Vol. 15 Issue 12, p122507 

    The physics of parallel heat transport was tested in the scrape-off layer (SOL) plasma of the National Spherical Torus Experiment [M. Ono et al., Nucl. Fusion 40, 557 (2000); S. M. Kaye et al., ibid. 45, S168 (2005)] tokamak by comparing the upstream electron temperature (Te) and density (ne)...

  • The accurate FROG characterization of attosecond pulses from streaking measurements. Gagnon, J.; Goulielmakis, E.; Yakovlev, V. S. // Applied Physics B: Lasers & Optics;Jul2008, Vol. 92 Issue 1, p25 

    We describe a new attosecond FROG algorithm optimized for the characterization of sub-100 as pulses from streaked electron spectra. We make improvements upon the treatment of the attosecond streaking spectrogram, and show that these are necessary in order to accurately characterize shorter...

Share

Read the Article

Courtesy of THE LIBRARY OF VIRGINIA

Sorry, but this item is not currently available from your library.

Try another library?
Sign out of this library

Other Topics