Technical Conference:
13 – 18 May 2018
15 – 17 May 2018

SC301 - Quantum Cascade Lasers: Science, Technology, Applications and Markets

Monday, 15 May
12:30 - 16:30

Short Course Level: Beginner

Instructor: Federico Capasso, Harvard Univ., USA

Short Course Description:

Quantum Cascade Lasers (QCLs) are fundamentally different from diode lasers due to their physical operating principle, which makes it possible to design and tune their wavelength over a wide range by simple tailoring of active region layer thicknesses, and due to their unipolar nature. Yet they use the same technology platform as conventional semiconductor lasers. These features have revolutionized applications (spectroscopy, sensing, etc.) in the mid-infrared region of the spectrum, where molecules have their absorption fingerprints, and in the far-infrared or so called Terahertz spectrum. In these regions until the advent of QCLs there were no semiconductor lasers capable of room temperature operation in pulsed or cw, as well high output power and stable/wide single mode tunability. The unipolar nature of QCL, combined with the capabilities of quantum engineering, leads to unprecedented design flexibility and functionality compared to other lasers. The physics of QCLs, design principles, supported by modeling, will be discussed along with the electronic, optical and thermal properties. State-of-the-art performance in the mid-ir and Terahertz will be reviewed. In particular high power CW room temperature QCLs, broadly tunable QCL, short wavelength MWIR QCLs and recent breakthroughs in THz room temperature operation will be presented. A broad range of applications (IR countermeasures, stand-off detection, chembio sensing, trace gas analysis, industrial process control, medical and combustion diagnostics, imaging, etc.) and their ongoing commercial development will be discussed.

Short Course Benefits:

This course should enable the participants to:

  • Describe underlying QC Laser physics, operating principles and fundamental differences between standard semiconductor lasers and QC lasers

  • Explain quantum design of the key types of QC lasers, which have entered real world applications, and how their electrical and optical properties can be tailored to optimize performance in the mid-infrared and THz regions.

  • Discuss experimental device performance, including physical limits, design constraints and comparison with theory and determine device characteristics (current-voltage and light-current curves; differential and power efficiency, threshold, gain and losses; spectral behavior, single mode operation; high speed operation)

  • Explain the basics of QC laser device technology: fabrication process, materials growth options

  • Illustrate the basics of a chemical sensing system; discuss applications of state-of the-art mid-infrared QC lasers to sensing and present several examples of QC laser commercialization

  • Discuss current and future markets of QC lasers

Short Course Audience:

Graduate students; qualified undergraduates (mostly senior level) majoring in EE or physics/applied physics;researchers in industry, academia and government labs; engineers, sales reps and technical managers.

Education: Undergraduate degree or a Ph.D or pursuing a Ph.D in EE, Physics or Applied Physics, with knowledge of introductory level semiconductor devices.

Instructor Biography:

Federico Capasso is the Robert Wallace Professor of Applied Physics at Harvard University, which he joined in 2003 after a 27 years career at Bell Labs where he did research, became Bell Labs Fellow and held several management positions including Vice President for Physical Research. His research has spanned a broad range of topics from applications to basic science in the areas of electronics, photonics, nanoscale science and technology including plasmonics and the Casimir effect.  He is a co-inventor of the quantum cascade laser. He has lectured widely including many short courses and tutorials. He is a member of the National Academy of Sciences, the National Academy of Engineering, a fellow of the American Academy of Arts and Sciences; his most recent awards include the King Faisal Prize, the Berthold Leibinger Future Prize, the Julius Springer Prize for Applied Physics, the APS Arthur Schawlow Prize and the IEEE Edison Medal.

Sponsored by: