Quantum Cascade Laser (IMAGE) Princeton University, Engineering School Caption Quantum cascade lasers are small and efficient sources of mid-infrared laser beams, which are leading to new devices for medical diagnostics and environmental sensing. Credit Frank Wojciechowski Usage Restrictions For journalistic use only. For commercial publishing rights, please contact Steven Schultz, sschultz@princeton.edu. License Licensed content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.