16 September 1999 Molecular spectroscopy using vertical-cavity surface-emitting diode lasers
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Proceedings Volume 3821, Environmental Sensing and Applications; (1999) https://doi.org/10.1117/12.364171
Event: Industrial Lasers and Inspection (EUROPTO Series), 1999, Munich, Germany
Abstract
The spectral characteristics of a series of different VCSELs emitting at 850 nm and 762 nm have been examined, to assess the potential of this new kind of semiconductor laser for use in laser spectroscopy and fundamental metrology, particularly for environmental and energy monitoring of combustion processes. Adequate polarization control, which is necessary for laser spectral purity, was provided through manufacture of a dumbbell or 'figure-of-eight' shaped active region of the lasers at 850 nm. Spectral lineshape and linearity of the frequency tuning have been examined with a variety of methods such as optical interferometry and heterodyning. Optical heterodyning was used to measure a minimum linewidth of 90 MHz FWHM for a 762 nm VCSEL during single mode operation. Deviations from linearity of up to some GHz of frequency tuning with current were observed with an original application of a Twyman-Green interferometer, with basic current tuning rates of 58 GHz/mA and 130 GHz/mA for an 850 nm and a 762 nm VCSEL, respectively. The frequency stability for a 762 nm device was measured to be approximately plus or minus 40 MHz. A possible problem for the use of VCSELs in wavelength modulation spectroscopy (WMS) is that due to their extremely high tuning rate with current: ultra-low noise current drivers must be used in order to achieve high sensitivity detection. The WMS absorption spectrum with VCSEL of a number of lines of the oxygen molecule at 760 nm have been registered and studied.
© (1999) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
A. Andersson-Faeldt, Marco Ghisoni, A. Jacobsson, Anders G. Larsson, Stefan Helge Lundqvist, A. Oelme, Leslie R. Pendrill, Christian Sandberg, F. Sjoestroem, Robert Tell, C. Tullin, Tomas Wahnstroem, "Molecular spectroscopy using vertical-cavity surface-emitting diode lasers", Proc. SPIE 3821, Environmental Sensing and Applications, (16 September 1999); doi: 10.1117/12.364171; https://doi.org/10.1117/12.364171
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