Title:
FOURIER SPECTROMETER HAVING A MULTI-MODE QUANTUM CASCADE LASER, AND METHOD FOR SPECTROSCOPIC ANALYSIS OF A SAMPLE
Document Type and Number:
WIPO Patent Application WO/2018/172391
Kind Code:
A3
Abstract:
The invention relates to a Fourier spectrometer for spectroscopically analysing a sample, comprising: a multi-mode quantum cascade laser (QCL) that has an active QCL region in a laser resonator, which is configured to generate laser light with emission frequencies according to a plurality of resonator modes of said laser resonator, an excitation device configured to electrically excite said active QCL region using an electric pump current, and a tuning device by means of which the resonator modes can be set; an interferometer for producing an interferogram on the basis of the laser light; a detector device for detecting the interferogram following interaction with the sample and for acquiring a detector signal containing the detected interferogram, within a detector measuring time; and an evaluation device that is configured to acquire a spectrum of the sample using a Fourier transform of the detected interferogram. The QCL tuning device is designed to periodically and spectrally vary the resonator modes, with a tuning time period of less than 1 minute, in a spectral tuning interval which is at least equal to the spacing between consecutive resonator modes of the laser resonator, the active QCL region is configured to generate laser light with emission frequencies in the range of 1 THz to 6 THz, wherein the emission frequencies of the laser light cover a spectral emission range of at least 50 GHz, and the detector device is designed to temporally average the detector signal over the tuning time period of the QCL tuning device. The invention also relates to a method for spectroscopically analysing a sample using the spectrometer.
Inventors:
RÖBEN BENJAMIN (DE)
HEMPEL MARTIN (DE)
LÜ XIANG (DE)
BIERMANN KLAUS (DE)
SCHROTTKE LUTZ (DE)
GRAHN HOLGER T (DE)
HEMPEL MARTIN (DE)
LÜ XIANG (DE)
BIERMANN KLAUS (DE)
SCHROTTKE LUTZ (DE)
GRAHN HOLGER T (DE)
Application Number:
PCT/EP2018/057105
Publication Date:
November 29, 2018
Filing Date:
March 21, 2018
Export Citation:
Assignee:
FORSCHUNGSVERBUND BERLIN EV (DE)
International Classes:
G01J3/453; G01J3/42; G01J3/433; H01S5/34
Other References:
M. WIENOLD ET AL: "Frequency comb operation of long-cavity terahertz quantum-cascade lasers", PROCEEDINGS OF SPIE, vol. 9767, 7 March 2016 (2016-03-07), 1000 20th St. Bellingham WA 98225-6705 USA, pages 97671A, XP055496067, ISSN: 0277-786X, ISBN: 978-1-5106-1533-5, DOI: 10.1117/12.2208128
GUREL K ET AL: "Characterization of a new frequency tuning and modulation mechanism for spectroscopy in a quantum cascade laser", 2016 CONFERENCE ON LASERS AND ELECTRO-OPTICS (CLEO), OSA, 5 June 2016 (2016-06-05), pages 1 - 2, XP033024374
H.-W. HÜBERS ET AL: "High Resolution Terahertz Spectroscopy with Quantum Cascade Lasers", JOURNAL OF INFRARED, MILLIMETER AND TERAHERTZ WAVES, vol. 34, no. 5-6, 4 April 2013 (2013-04-04), US, pages 325 - 341, XP055497352, ISSN: 1866-6892, DOI: 10.1007/s10762-013-9973-7
SCHROTTKE L ET AL: "Terahertz GaAs/AlAs quantum-cascade lasers", APPLIED PHYSICS LETTERS, A I P PUBLISHING LLC, US, vol. 108, no. 10, 7 March 2016 (2016-03-07), XP012205588, ISSN: 0003-6951, [retrieved on 19010101], DOI: 10.1063/1.4943657
BENJAMIN RÖBEN ET AL: "Terahertz quantum-cascade lasers as high-power and wideband, gapless sources for spectroscopy", OPTICS EXPRESS, vol. 25, no. 14, 29 June 2017 (2017-06-29), pages 16282, XP055496165, DOI: 10.1364/OE.25.016282
GUREL K ET AL: "Characterization of a new frequency tuning and modulation mechanism for spectroscopy in a quantum cascade laser", 2016 CONFERENCE ON LASERS AND ELECTRO-OPTICS (CLEO), OSA, 5 June 2016 (2016-06-05), pages 1 - 2, XP033024374
H.-W. HÜBERS ET AL: "High Resolution Terahertz Spectroscopy with Quantum Cascade Lasers", JOURNAL OF INFRARED, MILLIMETER AND TERAHERTZ WAVES, vol. 34, no. 5-6, 4 April 2013 (2013-04-04), US, pages 325 - 341, XP055497352, ISSN: 1866-6892, DOI: 10.1007/s10762-013-9973-7
SCHROTTKE L ET AL: "Terahertz GaAs/AlAs quantum-cascade lasers", APPLIED PHYSICS LETTERS, A I P PUBLISHING LLC, US, vol. 108, no. 10, 7 March 2016 (2016-03-07), XP012205588, ISSN: 0003-6951, [retrieved on 19010101], DOI: 10.1063/1.4943657
BENJAMIN RÖBEN ET AL: "Terahertz quantum-cascade lasers as high-power and wideband, gapless sources for spectroscopy", OPTICS EXPRESS, vol. 25, no. 14, 29 June 2017 (2017-06-29), pages 16282, XP055496165, DOI: 10.1364/OE.25.016282
Attorney, Agent or Firm:
V. BEZOLD & PARTNER PATENTANWÄLTE - PARTG MBB (DE)
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