Quantum Cascade Lasers created

Several types of lasers exist today that can emit at desired infrared wavelengths, none of these lasers meet requirements for some applications because they are either too expensive, not mass-producible, too fragile or require power-hungry and inefficient cryogenic refrigeration. Applications for suitably portable laser systems include the use of infrared countermeasures to protect aircraft from heat-seeking missiles and highly sensitive chemical detectors for reliable early detection of trace explosives and other toxins at a safe distance for personnel.

A new type of semiconductor-based laser, called the Quantum Cascade Laser (QCL) are compact and suitable for mass production and Manijeh Razeghi, Walter P. Murphy Professor of Electrical Engineering and Computer Science at the McCormick School of Engineering and Applied Science, has recently made great strides in laser design, material growth and laser fabrication that have greatly increased the output power and wall-plug efficiency (the ability to change electrical power into light) of QCLs.

Demonstrations have been made of individual QCL lasers, 300 of which can easily fit on a penny, emitting at wavelengths of 4.5 microns, capable of producing over 700 milli-Watts of continuous output power at room temperature and more than one Watt of output power at lower temperatures. The lasers are efficient in converting electricity to light, having a 10 percent wall-plug efficiency at room temperature and more than 18 percent wall-plug efficiency at lower temperatures.

1 thought on “Quantum Cascade Lasers created”

  1. They have the potential to use less power, but this recent breakthrough was to get them from impractical higher energy. Therefore, there is still work to be done to get to even less power.

    Nanowires have a smallish time window to have some impact. Intel is at a 65 nanometer process and will start 45 nanometer in 2007. Samsung has 40 nanometers for its latest NAND and is progressing towards 20 nanometers. These wires are 30 nanometers apart and they can get them to 15 nanometers and probably less.

    With the issues to get the nanowires scaled up and all of the detailed problems worked out. I think this will likely be a niche impact in the 4-10 year time span.

    For really low energy usage, whatever the new technology is needs to adopt reversible computing techniques.

  2. Sounds promising. Smaller, more powerful computers sound great. One thing that I am always look at in considering new computing paradigms is the amount of energy that the new cpu’s will use. In order to have an environment that is saturated with computers, especially mobile ones, we need low energy computing.

    Brian, any ideas on if nanowires would use less energy than current technology transistors do? The article mentions a little about power consumption of older nanowires but doesn’t go into any depth on the issue.


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