NRL funds QC laser development at Daylight

The US Naval Research Laboratory (NRL) has awarded laser system builder Daylight Defense a $5.7 million contract to develop quantum cascade laser (QCL) technology for military applications.

The San Diego company, a subsidiary of Daylight Solutions, will use QCLs to provide a novel system for infrared countermeasures (IRCM), with anticipated benefits in size, weight and power consumption.

"These systems showcase the capabilities that are inherent in our design approach, and will bring tremendous benefit in reliability, size, weight and power," said Daylight CEO Timothy Day.

Although many types of laser system can be deployed in IRCM applications, Daylight told optics.org that the reliability of its QCL systems versus existing technologies is one of the main reasons driving the use of the novel technology.

"What has really pulled the technology into the mainstream is related to the integration into full turn-key systems that have been ruggedized and demonstrated to perform over military environments," the company said.

With the optical and mechanical elements of Daylight's QCL systems already validated by the US military, the key remaining challenge is to fully integrate them within a complete IRCM system.

Modular designs
Daylight uses modular designs, meaning that any commercially available QC laser chips can be deployed inside its systems. "Specific epitaxial recipes vary, but [the lasers] are based, for the most part, on InGaAs/InP material systems," added the company. "As different vendors may be better at different parameters (e.g. wavelength selection, power, efficiency, etc), this allows us a great deal of flexibility when designing laser systems for a variety of customers and applications."

First developed by a team led by Al Cho and Federico Capasso at Bell Laboratories in 1994, QCLs have recently begun to gain significant traction in commercial spectroscopic applications, for example remote gas sensing and medical diagnostics.

QCLs can provide particularly sensitive detection of gases, and this is one of the focus areas of the Mid-InfraRed Technologies for Health and the Environment (MIRTHE) engineering research center based at Princeton University under the direction of Claire Gmachl - part of the Bell Laboratories team that first developed the QCL.

QC-based sensors under development at MIRTHE include monitors for urban air quality, breath analysis and greenhouse gases, for example.

Daylight backs up the notion that QC-based devices may be on the brink of widespread market penetration: "The whole area of mid-infrared applications is exploding," said the company. "Many chemical imaging applications such as cancer detection, pharmaceutical quality control and materials inspection can use external-cavity QCL technology."

"Others such as alcohol breath detection and glucose sensing, marine stack emissions monitoring, atmospheric monitoring and a variety of homeland security applications can also take advantage of these sensors."