EE Graduate Seminar

High Power Mid-Infrared Quantum Cascade Laser
Arrays for Standoff Photoacoustic Chemical Detection

Xing Chen, PhD (EE) Student
Computer Science and Electrical Engineering, UMBC

11:30am-12:45pm, Friday, 30 March 2012, ITE 237

Quantum cascade lasers (QCLs) are compact, powerful, mid-infrared, Semiconductor laser sources. High power QCLs are very important to infrared counter measures (IRCM) and standoff chemical detection applications, as well as others. The performance of such systems critically depend on the amount of power that QCLs can produce. One way to achieve high power operation is to use multi-emitter phase-locked laser arrays.

The first part of the seminar presents the issues and challenges to design, fabricate, and characterize multi-emitter phase-locked QCL arrays for achieving high power operation. The second part of the seminar discusses using high power mid-infrared QCLs to perform standoff photoacoustic (PA) chemical detection. The PA effect is a photo-matter effect involving generation and detection of an acoustic signal when a gas sample absorbs electromagnetic energy (particularly of light).

In recent years, with the help of the development of mid-infrared QCLs, significant progress has been made in their use for PA chemical detection, and sensitivity has been improved significantly. Our theoretical and experimental studies of standoff photoacoustic chemical detection, using QCLs as the laser source, will be presented.

Xing Chen received the BS degree in Opto-Electronics Engineering from Huazhong University of Science and Technology in 2007, and the MSEE degree from UMBC in 2009. He is currently a PhD (EE) candidate at UMBC. Mr. Chen's research interest includes design and fabrication of high power mid-infrared phase-locked QCL arrays and application to standoff photoacoustic chemical detection.

Host: Prof. Joel M. Morris