QC-ET Extended Tuning DFB Source

Alpes Lasers offers two types of extended tuning devices, both of which allow rapid tuning at fixed temperature in a wider range than standard DFB lasers. The QC-ET (described here) allows fully continuous tuning over 0.4% of the central wavelength, while the QC-XT allows piece-wise continuous tuning over 2% of the central wavelength.

QC-ET Extended Tuning Lasers use a dual current control to extend the mode-hop free tuning to more than 0.4% of the central wavelength (>6 cm-1 at 1270 cm-1). While the first laser input allows direct intensity modulation in the same manner as standard DFB lasers, the integrated heater current IT allows to offset the wavelength much faster than the temperature change of the heatsink temperature would do.

Key Benefits:
  • Increased wavelength scanning span fully electrically
    (Increased electrical wavelength scan)
  • Wavelength dither and ramps as in conventional DFB
  • DFB wavelength reproducibility
  • DFB quality linewidth and noise

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Take a look at these two sample datasheets to see how these ET-QCLs can be used, or read the following paper in Optics Express:


You can see in the picture on the right the extent of the range of a typical QC-ET laser compared to a standard DFB laser. By integrating the heater monolithically the entire range can be accessed at a fixed temperature.

nullThe current and amplitude in the laser and resistor can be combined to change the tuning range. Frequency tuning is maximized when the modulations are in phase and minimized when they are out of phase.
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nullThis type of modulation can be used to taylor the ratio of frequency and amplitude modulation to your experiment.

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