Invited Research Lecture: From Quantum Cascade Lasers to Plasmonic Laser Antennas and Collimators for Beam Engineering

Date: 19 Aug 2008 - 19 Aug 2008

Venue: SIMTech Training Room 2, Tower Block, Level 3


Professor Federico Capasso is one of the pioneers in the field of quantum cascade laser (QCL) which is a fundamentally new light source whose emission wavelength can be designed to cover the entire spectrum from mid to far infrared by tailoring the active region layer thickness. This light source is specifically useful in optical coherence tomography which is technology capable of seeing through sub-surface non-destructively.

The richness of the underlying basic physics of Quantum Cascade Lasers (QCL) combined with the capabilities of bandstructure engineering has led to unprecedented design flexibility and functionality compared to other lasers. State-of-the-art performance in the mid-ir and Terahertz will be reviewed. A broad range of applications (chembio sensing, trace gas analysis, atmospheric chemistry, medical and combustion diagnostics, THz imaging, etc.) and their ongoing commercial development will be discussed. The speaker will share his insight into the recent exciting developments such as room temperature THz QCL based sources using difference frequency generation and broadband on-chip laser spectrometers lasers. 

The second part of the presentation will focus on a new class of light-sources in which the near-and far-field properties are fundamentally altered by means of plasmonic structures monolithically integrated on the laser facet. As a platform to demonstrate these beam shaping concepts we have used state-of-art QCLs and diode lasers but these ideas are broadly applicable to other solid-state lasers. A dramatic reduction in beam divergence by a factor in excess of 25 and full beam collimation has bean achieved using suitable aperture-groove metallic structures on the facet of QCLs. 

Plasmonic laser antennas capable of concentrating light in ultrahigh-intensity near-field nanospots for a broad class of applications (optical storage, nanoscale chemical imaging, etc.) will also be demonstrated. This lecture is co-organised by the National Metrology Centre, A*STAR.

About the Speaker
Professor Federico Capasso received his PhD in Physics, summa cum laude, from the Unviersity of Rome in 1973. After completing his research in fiber optics at Fondazione Bordoni in Rome, he joined Bell Labs in 1976. In 1984, he was made a Distinguished Member of Technical Staff and in 1997 a Bell Labs Fellow. He holds an honorary doctorate in Electronic Engineering form the University of Bologna, Italy.

In addition to his research commitments, Professor Capasso has held several management positions at Bell Labs including Head of the Quantum Phenomena and Device Research Department and the Semiconductor Physics Research Department (1987-2000) and Vice President of Physical Research (2000-2002). Professor Capasso is an academic member of Harvard University since 1 January 2003. 

Professor Capasso is internationally well known for his pioneering research work on bandstructure engineering of artificially structured semiconductors and devices, which has opened up new directions in materials research, mesoscopic physics, photonics, electronics, and nanotechnology. Together with his collaborators, they invented and developed the quantum cascade laser, a fundamentally new light source, which is now commercial and has potentially wide ranging applications to trace gas analysis and chemical sensing (atmospheric chemistry, combustion diagnostics, pollution monitoring, industrial process control, medical diagnostics, homeland security) and telecommunications. 

His current research in quantum electronics deals with the design of new light sources based on giant optical nonlinearities in quantum wells such as Raman injection lasers, inversioless injection lasers and widely tunable sources of TeraHertz radiation based on difference frequency generation and Raman lasers. He has also carried out research on quantum chaos in deformed microlasers which led him and his collaborators to invent microlasers operating on bow-tie modes. More recently his research has expanded to high-precision measurements of Casmir forces using MEMS (MicroElectroMechanicalSystems) and other quantum electrodynamical effects such as the torque between birefringent materials due to vacuum fluctuations. 

His professional affiliations include membership in the National Academy of Sciences, the National Academy of Engineering, the American Academy of Arts and Sciences, The European Academy of Sciences and honorary membership in the Franklin Institute. 

Professor Capasso has been awarded numerous accolades, most notably in 2005 he received, jointly with Nobel Laureate Frank Wilczek (MIT) and Anton Zeilinger (University of Vienna), the prestigious King Faisal International Prize for Science for his research on quantum cascade lasers. The citation called him “one the most creative and influential physicists in the world”. 

On behalf of the American Physical Society, he was awarded the 2004 Arthur L. Schawlow Prize in Laser Science endowed by the NEC Corporation for "seminal contributions to the invention and demonstration of the quantum cascade laser and the elucidation of its physics, which bridges quantum electronics, solid-state physics, and materials science." 

In recognition of his achievements, the IEEE (Institute of Electrical and Electronics Engineers), the world's largest technical professional organisation, named Capasso the recipient of the 2004 IEEE Edison Medal with the following citation, "For a career of highly creative and influential contributions to heterostructure devices and materials." 
For the IEEE Spectrum’s 40th anniversary commemorative issue, Capasso was interviewed along with 38 other leading thinkers from the science and engineering world and asked to gaze out over the technology landscape and describe what they see. 

He is also the recipient of the Wetherill Medal of the Franklin Institute, the R. W. Wood prize of the Optical Society of America, the IEEE Laser and Electro-Optics Society W. Streifer Award for Scientific Achievement, the Materials Research Society Medal, the Rank Prize in Optoelectronics (UK), the Duddell Medal and Prize of the Institute of Physics (UK), The Willis Lamb Medal for Laser Science and Quantum Optics, the Newcomb Cleveland Prize of the American Association for the Advancement of Science, the Moet Hennessy and Lois Vuitton "Leonardo da Vinci" Prize (France), the Welker Memorial Medal (Germany), the New York Academy of Sciences Award, the IEEE David Sarnoff Award in Electronics, and the Goff Smith prize of the University of Michigan. He received the Bell Labs Fellow and the Bell Labs Distinguished Member of Technical Staff Awards. 

A Fellow of the American Physical Society, the Institute of Physics (UK), the Optical Society of America, the American Association for the Advancement of Science, IEEE and SPIE, Professor Capasso has co-authored over 300 papers, edited four volumes; and holds over 50 US patents. 

2.15pm : Registration

2.35pm:  Introduction by Dr Kok Shaw Wei, Precision Measurements Group

2.45pm:  Presentation Part 1: Quantum Cascade Lasers to Plasmonic Laser 
              Antennas and Collimators for Beam Engineering

3.45pm:  Tea Break & Networking

4.00pm:  Presentation Part 2: Quantum Cascade Lasers to Plasmonic Laser
              Antennas and Collimators for Beam Engineering

5.00pm:  End

Who Should Attend
Researchers and scientists, engineers, R&D managers, industry practitioners, academic professionals and engineering students.

Pre-registration for the lecture is necessary. Seats are available on a first-come-first-served basis.

For technical enquiries: 
Dr Kok Shaw Wei, Email:

For registration and general enquiries: 
Alice, Email: