Extended Tuning Laser – Alpes Lasers

Extended Tuning Laser
QC-ET

Range of a typical QC-ET laser compared to a standard DFB laser.

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 DFB Sources 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.

You can see in the picture on the left 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.

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

To get more information about the technology behind the QC-XT lasers you can read the following paper:

A. Bismuto, Y. Bidaux, C. Tardy, R. Terazzi, T. Gresch, J. Wolf, S. Blaser, A. Muller, and J. Faist, “Extended tuning of mid-ir quantum cascade lasers using integrated resistive heaters,” Optics Express, vol. 23, no. 23, p. 29715, Nov. 2015