Alpes Lasers introduces a new class of Extended Tuning DFB, the QC-ET. These QC-ET 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 Features

• Wavelength and power independent control

• Standard DFB tuning

• Extended tuning at constant heat-sink temperature 

Key Applications

• Increased wavelength scanning span fully electrically

• Wavelength dither and ramps as in conventional DFB

• DFB wavelength reproducibility

• DFB linewidth and noise 

The QC-ET devices provide a larger tuning than a conventional DFB at a single heat-sink temperature. These devices provide the ability to tune fully electrically the emission wavelength without changing the heat-sink temperature. The dots in the figure show the power at a given emission wavelength and heat-sink temperature for the device used as a conventional DFB i.e.without wavelength current tuning IT . The shadowed area shows the attainable wavelength and power region for various tuner current (IT). This area is attainable without changing the heat-sink temperature, widely increasing the speed at which a region of the spectrum may be scanned. Using proper ramps for the laser and tuner current the whole region may be explored at once with speeds in the 100 Hz to kHz range. 

Example of wide scanning of a N2O gas cell, with fast IL scans and independent IT values.