LONG BEACH, CA-From quantum physics and nanophotonics to homeland security, optical coherence tomography (OCT), and fiber lasers, the 2006 CLEO/QELS conference offered a well-balanced mix of the “state of the art” in lasers and optoelectronics and their real-world applications. The 5200 attendees-on par with last year’s attendance figures, according to show organizers the Optical Society of America (OSA; Washington, DC)-were treated to more than 200 technical sessions and 2180 paper submissions, plus a busy exhibit hall filled with more than 300 companies and organizations showcasing their products and services. In addition, the PhAST conference provided an excellent overview of where lasers and optoelectronics are being used today, from manufacturing and homeland security to biophotonics and nanofabrication (see p. 3).
Focus on imaging
Aptly titled “The Future of Imaging,” Tuesday’s Press Luncheon at the 2006 CLEO Conference convened a distinguished group of presenters with information on breakthrough technologies in the world of imaging science. It turns out that the ability to image deep within biological tissue, and to distinguish individual molecules by analyzing breath samples, are two seemingly futuristic capabilities that are possible today thanks to OCT advances, and cost-effective quantum cascade lasers, respectively. These and other important technologies-spanning the electromagnetic spectrum from the mid-infrared through the visible and into the terahertz region-were presented by Tim Day, CEO, CTO & chairman of the board of directors of Daylight Solutions (Poway, CA), James Fujimoto, professor of Electrical Engineering and Computer Science at the Massachusetts Institute of Technology (MIT; Cambridge, MA), and David Zimdars, manager of Terahertz R&D at Picometrix (Ann Arbor, MI).
Daylight Solutions began the Press Luncheon with “Commercializing the mid-IR,” an overview of their new “tiny tunable” quantum-cascade lasers and the optical sensing products they are helping to commercialize. As the winner of the 2006 PhAST/Laser Focus World Innovation Award, Daylight Solutions is applying their new lasers to molecular breath analysis, glucose monitoring, and explosives detection.
(The Innovation Award also recognized four other companies with honorable mentions: Sacher Lasertechnik for development of a commercial diode-laser based portable source for terahertz generation, Thorlabs for introducing a complete OCT system capable of two- and three-dimensional imaging and diagnosis of a sample’s internal optical properties, PolarOnyx for creating a 100 mJ femtosecond fiber laser and impacting future fiber laser applications, and Fianium for showcasing important advancements in the fiber laser market and demonstrating potential new markets and applications that require spectral brightness which was previously impossible to achieve.)
James Fujimoto continued the presentations with “OCT: an emerging technology for biomedical imaging and optical biopsy.” His talk began with details on OCT techniques as they primarily apply to ophthalmology, noting that ultrahigh resolution OCT has improved the resolution from 10 mm down to 2-3 mm and enabled more detailed images of the eye, as well as other tissue regions towards non-invasive detection of cancer and other diseases.
David Zimdars concluded the presentations with “Security and non-destructive evaluation application of high-speed time-domain terahertz imaging,” discussing one of the most exciting areas of research and product development today in photonics. In the quest to see through wood, plastics, and metals, terahertz imaging techniques are moving out of the laboratory and into commercial use in a variety of inspection and security-related applications. Although much progress has been made in this wavelength region, terahertz technology is definitely something to watch in the future.
Ultrafast everywhere
For laser and laser-related component and service providers, CLEO always provides a plethora of new product introductions. And, with 310 exhibitors on the show floor, 2006 did not disappoint.
New laser product offerings included the ultrafast petaWatt glass phosphate flash-lamp pumped Ti:Sapphire laser system from Thales Laser (Orsay, France) called ATLAS, delivering an energy of 50 J at 527 nm with a pulse duration less than 20 ns and a repetition rate up to 0.1 Hz and with supervision software fully compatible with their Ti:Sapphire femtosecond laser series, as well as the StableWave and Velocity tunable lasers from Bookham (San Jose, CA) which are new models of the New Focus Velocity tunable lasers at 894 and 795 nm for cesium and rubidium transitions and many other new wavelengths for precision optical metrology and interferometry. In addition, Hamamatsu (Bridgewater, NJ) introduced quantum cascade lasers ready for incorporation into OEM laser systems for environmental gas monitoring and other applications.
Bookham also introduced detector and laser-based accessories including new high-speed avalanche photodiode (APD) receivers for ultralow-light-level detection applications and Tiny Picomotor Actuators, designed to move up to 3.0 lbs from within a tiny footprint. Low-light measurements are also the focus for Hamamatsu with their 10 mm X 10 mm active-area APD for high sensitivity and high gain, along with their R9110 photomultiplier tube that provides high performance from the ultraviolet to the near-IR.
Coherent (Santa Clara, CA) introduced a Silhouette standalone pulse controller, based on a spatial light modulator, with an optical platform that provides closed-loop measurement and optimization of both the spectral phase and amplitude of ultrafast pulses. The Silhouette acquires data through a low profile, fiber-coupled sensor enabling pulse characteristics to be monitored and controlled at any location within an ultrafast setup-even at the output of an oscillator or amplifier or after beam delivery optics. Other ultrafast introductions from Coherent included an oscillator delivering more than 3 W of output power, and a non-collinear optical parametric amplifier that delivers widely tunable output from the UV through the near IR, providing a simplified route to pulse widths shorter than 25 fs, even when pumped by Ti:Sapphire ultrafast amplifiers having pulse widths longer than 100 fs.
Also in the ultrafast regime, Spectra-Physics (Mountain View, CA) introduced the Spitfire Pro XP and the Spitfire Pro 5W ultrafast amplifiers. Both utilize a one-Pockels cell regenerative cavity design that “reduces intra-cavity dispersion and losses to deliver unprecedented specifications for regenerative amplification,” according to product manager Julien Klein. “They are an ideal solution for ultrafast applications such as multicolor pump-probe studies, nonlinear optics, pumping of optical parametric amplifiers, and precision material processing.”
Spitfire Pro XP uses chirped-pulse and regenerative amplification to generate sub-35 fs pulses in a near TEM00, near transform limited output beam with more than 3 mJ at 1 kHz. The Spitfire Pro 5W features a hybrid architecture that combines the benefits of a regenerative cavity and of a multipass amplification to provide a near TEM00, near transform limited output beam of sub-40 fs, sub-120 fs, or picosecond pulses with more than 5 mJ at 1 kHz. “The Spitfire Pro 5W’s enhanced design is so efficient that it eliminates the need for expensive cryogenic cooling systems common in other high power amplification systems,” Klein said.
Spectra-Physics also announced a CW tunable single-frequency ring laser with an external reference cavity to lock the laser wavelength and spectral bandwidth within 500 kHz targeted for scientific research applications such as high-resolution spectroscopy, frequency time standards, Bose-Einstein condensates, atomic cooling, and optical memory and computing research. The overall tuning range extends from 550 to 1000 nm.
Among ultrafast fiber laser introductions, IMRA America (Ann Arbor, MI) launched a fiber chirped pulse amplification (FCPA) µJewel D-1000, offering up to 10 µJoule level pulse energy at near IR wavelength, and a capability for users to select repetition rates between 100 kHz and 5 MHz, as well as to between high-energy operation with 10 µJoule pulses at 100 kHz or 1 µJoule at 1 MHz. The options allow for material processing of harder materials or at faster rates, depending upon the application requirements.
IMRA also announced an agreement with the University of Aachen (Aachen, Germany) to create a premier application laboratory (PAL) to perform feasibility studies using advanced ultrafast fiber lasers in Europe and collaborative research into material processing applications.
-Kathy Kincade, Gail Overton, Hassaun Jones-Bey