Princeton University

School of Engineering & Applied Science

Gerard Wysocki

Director of MIRTHE+

Associate Professor of Electrical Engineering

Room: B324 Engineering Quadrangle
Phone: 609-258-8187
Webpage: Wysocki Lab: Princeton University Laser Sensing (PULSe)


  • Ph.D., Johannes Kepler University, Linz, Austria, 2003
  • M.S., Electronics, Faculty of Electronics, Wroclaw University of Technology, Wroclaw, Poland, 1999

My current research interests focus on the development of laser-based spectroscopic systems for chemical sensing, with a strong emphasis on real-world applications in atmospheric chemistry and environmental monitoring, bio-medical research, and industrial process control. Many interesting new applications will be enabled by trace-gas sensors that are fast, compact, field-deployable, sensitive, and selective. Laser-based spectroscopic sensor systems have an excellent potential to address all those needs and provide noninvasive, rapid chemical analysis of the sample of interest both remotely or in-situ. The main research areas explored by my group are:

  • Development of new optical instrumentation, spectroscopic measurement methods, and data-analysis techniques
  • Implementation of novel laser sources such as quantum cascade lasers or interband cascade lasers
  • Investigation of new applications in interdisciplinary research areas
  • Exploration of modern photonics technologies, materials, and devices
  • Efficient transfer of novel technologies and fundamental science discoveries to applications

The development of laser spectroscopic techniques strongly relies on increasing the availability of new laser sources. Therefore, one of my research directions is focused on development of widely tunable mid-infrared external cavity quantum cascade lasers (EC-QCLs) for high-resolution spectroscopic applications in chemical analysis. This technology enables new applications that represent a significant challenge for spectroscopists with existing laser sources (i.e., detection of complex molecules with broadband unresolved ro-vibrational absorption bands, simultaneous detection of multiple molecular species, and spectroscopy of liquid/solid samples). EC-QCLs with tuning ranges up to 15% of the center wavelength and output powers up to 50mW were recently demonstrated in various spectroscopic applications, such as photoacoustic detection of broadband absorbers and high-resolution (< 0.001 cm-1) Faraday rotation spectroscopy of nitric oxide. In the case of single-sampling-point trace-gas monitoring, lack of spatial information makes it impossible to localize specific emission sources (e.g., accidental gas leaks or unauthorized industrial emissions). The deployment of a sensor network will enable continuous spatial trace-gas monitoring of a large geographical area, providing complete static (concentration) and dynamic (fluxes, sources, and sinks) information about target analytes. In one of our current research projects we are developing a low-power, miniature spectroscopic trace-gas sensor for wirelessly communicating distributed sensor networks. Off particular interest in this research effort are ultra-sensitive spectroscopic techniques, application of novel optoelectronic devices, power-efficient electronics for data acquisition and signal processing, and integration at both the device and the system level.

Honors and Awards

  • STAR Program Early Career Award from the U.S. EPA (2012)
  • The second prize for innovation by the Princeton's Keller Center for Innovation in Engineering Education (2009 and 2012)
  • The Finalist for the Blavatnik Award of the New York Academy of Sciences (2011)
  • NSF Early Career Award (2010)
  • Masao Horiba Award, Japan (2010)
  • NASA Tech Brief Initial award (2010)
  • NASA Certificate of Recognition for the creative development and the invention disclosure (2008)

Selected Publications

  1. M. Nikodem, and G. Wysocki, "Measuring optically thick molecular samples using chirped laser dispersion spectroscopy," Optics Letters 38, 3834-3837 (2013)

  2. Y. Wang, M. Nikodem, and G. Wysocki, "Cryogen-free heterodyne-enhanced mid-infrared Faraday rotation spectrometer," Opt. Express 21, 740-755 (2013)

  3. M. Nikodem, G. Plant, Z. Wang, P. Prucnal, and G. Wysocki, "Chirped lasers dispersion spectroscopy implemented with single- and dual-sideband electro-optical modulators," Opt. Expr. 21, 14649-14655 (2013)

  4. B. Brumfield, W. Sun, Y. Ju, and G. Wysocki, "Direct In Situ Quantification of HO2 from a Flow Reactor," The Journal of Physical Chemistry Letters 4, 872-876 (2013)

  5. C. J. Smith, S. So, L. Xia, S. Pitz, K. Szlavecz, D. Carlson, A. Terzis, and G. Wysocki, "Wireless laser spectroscopic sensor node for atmospheric CO2 monitoring—laboratory and field test," Appl. Phys. B 110, 241-248 (2013)

  6. T. R. Tsai, R. A. Rose, D. Weidmann, and G. Wysocki, "Atmospheric vertical profiles of O3, N2O, CH4, CCl2F2, and H2O retrieved from external-cavity quantum-cascade laser heterodyne radiometer measurements," Appl. Opt. 51, 8779-8792 (2012)

  7. M. Nikodem, D. Weidmann, and G. Wysocki, "Chirped laser dispersion spectroscopy with harmonic detection of molecular spectra," Appl. Phys. B 109, 477-483 (2012)

  8. M. Nikodem, D. Weidmann, C. Smith, and G. Wysocki, "Signal-to-noise ratio in chirped laser dispersion spectroscopy," Opt. Expr. 20, 644-653 (2012)

  9. B. Brumfield, and G. Wysocki, "Faraday rotation spectroscopy based on permanent magnets for sensitive detection of oxygen at atmospheric conditions," Opt. Expr. 20, 29727-29742 (2012)

  10. D. Weidmann, T. Tsai, N. A. Macleod, and G. Wysocki, "Atmospheric observations of multiple molecular species using ultra-high-resolution external cavity quantum cascade laser heterodyne radiometry," Opt. Lett. 36, 1951-1953 (2011)

  11. S. So, E. Jeng, and G. Wysocki, "VCSEL based Faraday rotation spectroscopy with a modulated and static magnetic field for trace molecular oxygen detection," Appl Phys B 102, 279-291 (2011)

  12. G. Wysocki, and D. Weidmann, "Molecular dispersion spectroscopy for chemical sensing using chirped mid-infrared quantum cascade laser," Opt. Expr. 18, 26123-26140 (2010)

  13. R. F. Curl, F. Capasso, C. Gmachl, A. A. Kosterev, B. McManus, R. Lewicki, M. Pusharsky, G. Wysocki, and F. K. Tittel, "Quantum cascade lasers in chemical physics," Chem Phys Lett 487, 1-18 (2010)

  14. D. Weidmann, G. Wysocki, “High-resolution broadband (>100 cm-1) infrared heterodyne spectro-radiometry using an external cavity quantum cascade laser”, Opt. Express 17, 248 (2009)

  15. R. Lewicki, J. H. Doty, R. F. Curl, F. K. Tittel, G. Wysocki, “Ultrasensitive detection of nitric oxide at 5.33 mm by using external cavity quantum cascade laser-based Faraday rotation spectroscopy”, Proceedings of the National Academy of Sciences 106, 12587 (2009).

  16. A. Kosterev, G. Wysocki, Y. Bakhirkin, S. So, R. Lewicki, M. Fraser, F. Tittel, R. F. Curl, “Application of quantum cascade lasers to trace gas analysis”, Applied Physics B: Lasers and Optics 90, 165 (2008).

  17. G. Wysocki, R. Lewicki, R. F. Curl, F. K. Tittel, L. Diehl, F. Capasso, M. Troccoli, G. Hofler, D. Bour, S. Corzine, R. Maulini, M. Giovannini, J. Faist, “Widely tunable mode-hop free external cavity quantum cascade lasers for high resolution spectroscopy and chemical sensing”, Applied Physics B: Lasers and Optics 92, 305 (2008).