Tunable IR Semiconductor Laser Sources

In the wavelength region longer than 3 microns there are two types of tunable semiconductor lasers.  These are Quantum Cascade Lasers (QCLs, which operate at on near room temperature) and Lead salt lasers (Pb-salts, which require operation at cryogenic temperatures).  We offer both types.

Quantum Cascade Lasers

(A) DEVICES: Our QCLs are from Alpes Lasers SA in Switzerland.  You can visit their web site at www.alpeslasers.com.   QCLs are a recent development and Alpes is the principle commercial provider.  The following table summarizes the currently available products.  The cost of a room temp pulsed QCL plus hardware to house and drive it is about the same as for a Pb-salt laser plus variable temp cryostat and drive electronics.

For a list by wavelength of room temp PULSED DFB types available for fast (2-3 weeks) delivery, click here.

For a list by wavelength of CW Cryogenic DFB singlemode devices in stock for fast delivery, click here!

At the 2003 Workshop on QCL Lasers held in Freiburg Germany, Alpes made a presentation which documents the current state of the art, click here for a copy.

For a reasonably good summary of the Alpes product line, click here and open our 2.7 MB pdf format 66 page brochure. This file includes the "FAQ" below and the 2003 Workshop presentation above.  One stop shopping!

If you have questions, please email or phone us.  But we also note that your questions may be ones that have been asked before.  For a "FAQ" document, please click here.

QCLs are made on wafers.  Each wafer can contains many devices of similar performance (and more that do not work at all - that is "yield" or lack thereof).  Alpes has now build QCLs at a number of wavelengths in the 5 to 10+ micron region.  We encourage you to ask what wavelengths are available in semi-fabricated form as if one meets your needs it will be less expensive and faster delivery than an entirely new one.

(B) HARDWARE: Alpes offers a "starter kit" of hardware to stabilize the device temperature at any temp from -30C to +30C and to energize (drive) the device.  Details of the "starter kit" are contained in the brochure linked above.  For the USER MANUAL, CLICK HERE.

Pb-salt Lasers

We sell cryogenic systems into which Pb-salt laser diodes are placed and operated.  They considt of an LN2-based variable temperature cryostat plus associated control electronics.  The control electronics both controls the temperature of the diode in the cryostat but also provides power, typically pulsed, to drive the laser diode.  Temperature and diode current controllers work together to spectrally tune the diode.  These are made in Germany by Mütek Infrared Laser Systems. Typically our customers provide us with Pb-salt diodes that they have purchased from Laser Components GmbH (the only commencial Pb-salt laser producer) so that we can mount and test them inside the cryogenic system.

Pb-salt laser diodes are available for spectral regions between about 3.1 and 20 microns but ones suitable for use in LN2 cryostats are limited to about 3.1 to 10 microns.  .

Pb-salt laser diodes operate at cryogenic temperatures. Coarse tuning is by changing temperature and fine tuning is by current modulation. Output power is normally guaranteed as >100 microwatts.

Mütek's TDL source units typically consist of: variable temperature cryostat, cryostat temperature controller, laser diode current driver, base plate and collimating optics into which up to 2 Pb-salt tunable diode lasers (TDLs) are mounted.

This system is not for everyone, since it is both expensive and logistically complicated. A source unit alone based on bulk LN2 cooling with a single customer supplied TDL installed and tested costs ~$22,000. To achieve broad spectral coverage, several TDLs are needed as a typical TDL tunes over <200 cm^-1.

They are normally optimized for applications that require the very narrow line width of the TDL, which is ~0.001 cm^-1 and thus provides extremely high spectroscopic resolution.

• Mütek OLS-150 Tunable IR-Laser Source