The Color of Heat: How Quantum Cascade Lasers Solve the DoD’s Problem in Aircraft Protection

April 26, 2023

Leonardo DRS radars

A new laser technology has found its way into commercial production. Dubbed “quantum cascade laser” or “QCL”, this revolutionary technology has the potential to have a profound, positive effect for military aircraft survivability.

The infrared (IR) region of the electromagnetic spectrum is full of critical information that can be used to provide protection of U.S. and allied forces. For example, both fixed and rotary wing aircraft utilize signature information contained in the IR for the detection and defeat of heat-seeking missiles. IR sensors that provide situational awareness, targeting and other mission critical functions for platforms in the air, on the ground and at sea have become ubiquitous.

Lasers have long played a role in military operations. In the late 1960’s, shortly after the invention of the laser itself, laser designators began seeing action to provide high precision guidance of laser guided munitions. Many applications have followed, including range finding and aiming, in addition to more sophisticated designation. More recently, applications such as laser-based directed infrared countermeasures (DIRCM) have found their way into operational use. To date, many of these military applications involving lasers have remained relatively unchanged since the 1960’s.

Electromagnetic SpectrumOver the last ten years, a new laser technology has found its way into commercial production. Dubbed “quantum cascade laser” technology (named after its unique cascading effect to generate IR light), or “QCL”, this revolutionary approach has the potential to have a profound, positive effect for military capabilities. QCLs generate laser emission by converting electrical current directly into IR radiation. This is in contrast to legacy solid-state lasers that require several frequency conversion stages in order to generate emission in the IR, which leads to size, weight, power and reliability deficiencies in comparison.

QCLs have been demonstrated in several military applications protecting our soldiers and citizens. They have been demonstrated on aircraft platforms and integrated into multi-spectral beacons that provide combat identification. Wavelength-tunable variants of QCL-based sensors have been demonstrated in stand-off detection applications to detect chemical agents, explosive precursors and residues. Early-stage development of applications such as free-space communications, LADAR for degraded visual environments, and counter-UAS have also leveraged recent QCL-based products.

QCL technology is revolutionizing the way we design and implement protection and survivability products for the warfighter. Based upon conventional semiconductor laser technology (compact, millimeter-scale components), QCL-based products are inherently rugged and have been demonstrated to meet military environmental requirements. Systems that are based upon QCL devices provide operational capabilities across the IR spectrum, providing freedom of operation that is critical to support current and future engagements.