CLEO/QELS, PhAST break scientific barriers

BALTIMORE, MD-The Press-Only Luncheon at this year’s Conference on Lasers and Electro-Optics/Quantum Electronics and Laser Science Conference & Conference on Photonic Applications, Systems and Technologies (CLEO/QELS & PhAST) was appropriately entitled “New Fundamentals: Breaking Scientific Barriers.

BALTIMORE, MD-The Press-Only Luncheon at this year’s Conference on Lasers and Electro-Optics/Quantum Electronics and Laser Science Conference & Conference on Photonic Applications, Systems and Technologies (CLEO/QELS & PhAST) was appropriately entitled “New Fundamentals: Breaking Scientific Barriers.” In his opening remarks, Ben Stein from the Media & Government Relations Division of the American Institute of Physics (AIP; College Park, MD) said that only in the last ten years-thanks to the removal of certain nano-scale and attosecond-scale barriers in the photonics industry-have scientists actually been able to demonstrate such theorized classical experiments as terahertz and attosecond-scale imaging, visualization of chemical processes within the human body, and negative refraction.

The luncheon included presentations by Scott Barry of Thorlabs (Newton, NJ), who spoke about his company’s 2007 PhAST/Laser Focus World Innovation Award-winning technology-the Thorlabs adaptive scanning optical microscope (ASOM)-which addresses the centuries-old problem of field of view and resolution tradeoff in optical microscopes. By adding a MEMS-based adaptive optic in its ASOM, Thorlabs obtains high resolution in a very large field of view and can tackle imaging tasks (such as automatically tracking a moving worm) that were once extremely difficult with conventional microscopy technologies.

Boasting a record year for paper submissions, CLEO/QELS & PhAST 2007 treated its 5200 attendees to over 1800 technical presentations and more than 250 exhibitor booths to highlight the barrier-breaking field of lasers and photonics. There were more than 200 technical sessions and 200+ exhibitor booths to highlight the barrier-breaking field of lasers and photonics. While negative refraction in the visible may not yet enable the “cloaking” of objects, and while terahertz imaging may still require some detector improvements before large-scale deployment, there is a feeling in the photonics community that such capabilities are no longer impossible but probable.

In the Wednesday morning plenary session for the CLEO portion of the conference, William Philips from the National Institute of Standards and Technology (NIST; Gaithersburg, MD) discussed “Spinning Atoms with Light.” The advent of the laser and its subsequent improvement to ultrafast speeds and custom beam profiles makes it possible to illuminate a cloud of atoms (a Bose-Einstein condensate, or BEC) with two laser beams and transfer the orbital and angular momentum of the laser to the BEC cloud. This BEC vortex creates a toroidal trap and can be used to manipulate individual atoms using light-a feat that has applications in optical tweezers, atom optics, and quantum information processing.

New products

Femtolasers (Vienna, Austria) exhibited its Femtopower Pro CEP (carrier envelope phase) stabilized ultrafast amplifier that includes a difference-frequency-generation femtosecond oscillator that generates sub-7 fs pulses; the amplifier rebroadens the spectrum and recompresses the pulses to a pulse energy of 300 µJ or greater at sub-7 fs pulse durations. Coherent (Santa Clara, CA) also showed a CEP stabilized ultrafast laser, the Micra-CEP. The Coherent laser’s CEP detection module uses a photonic-crystal fiber to generate an octave-spanning optical spectrum. The red end of the spectrum is frequency-doubled and combined with the green end; the resultant beat frequency is sensed by a fast photodetector that provides the CEP feedback signal, used to control a fast cavity-mirror actuator to control the carrier phase. Uses of these lasers include attosecond pulse generation, high-harmonic generation, coherent terahertz generation, optical clocks, and other applications.

KMLabs (Boulder, CO) introduced its Wyvern ultrafast regenerative laser amplifier-a single-box system that uses patented downchirped pulse amplification (DPA) to enable sub-50 fs pulses from 50-200 kHz with m-squared less than 1.3. And to measure those pulses, Spectrum Detector (Lake Oswego, OR) debuted its analog joulemeters and digital USB joulemeters as well as its family of optical trap detectors with spectral ranges from 0.2 to 1.1 µm.

Holochip (Palo Alto, CA) showed a fluid-based lens that is continuously variable in focal length from infinity to approximately 50 mm; the lens contains a fluid that is held by a flexible membrane. The prototype had a clear-aperture diameter of about 10 mm, but the technology is scalable up to 25 mm diameters and down to less than a millimeter. While suitable for uses such as cell-phone cameras, the lens is rugged and simple enough to be used as a general singlet lens in the laboratory. The wavefront quality is currently half-wave peak-to-valley, and is being improved.

But the most tangible new products on display at CLEO/QELS & PhAST had to be the fully functional demonstration of the Thorlabs ASOM, as well as an improved T-Ray Model 4000 hand-held or table-top capable time-domain terahertz system from Picometrix (Ann Arbor, MI), which operates from 0.02 to 2 THz and includes software for time domain, fast Fourier transform, and absorbance analysis of samples under test.

Next year

Starting in August 2007, researchers and developers can begin submitting papers to CLEO/QELS & PhAST 2008, which will be held from May 4-9 in San Jose, CA.

-Gail Overton & John Wallace

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