Photonics West connects applications to technology
Exhibit-hall forums offer practical demonstrations, and technical sessions cover lasers, optoelectronics, electronic imaging, and life sciences technologies.
Laser Focus World staff report
A specialist wearing a head-mounted display sits comfortably in a chair while colleagues sit nearby in front of a high-resolution projection display screen. At the same time, in a rural village thousands of miles away, a field technician carefully places a head-mounted, diode-laser-based ophthalmic surgical device on a patient with an eye disorder. Using cameras, video compression, and other photonics instruments, the specialist guides the technician through a delicate medical procedure while colleagues watch and learn.
Sound futuristic? Actually it`s state-of-the-art telemedicine and is an example of the synthesis between optoelectronic and imaging technologies and life science applications that lies at the heart of Photonics West (San Jose, CA). In addition to the 2100 technical papers that will be presented at 80 conferences running from January 28 through February 2, live demonstrations designed to bring such applications to life will be featured in Town Squares on the exhibit floor.
Three technical programs define the primary themes at Photonics West: Lasers and Optoelectronics (O/E LASE), Electronic Imaging Science and Technology (EI S&T), and Biomedical Optics (BiOS). These themes will be reflected in the booth displays of the 350 to 400 exhibiting companies.
Lasers and optoelectronics
Due to rapid growth in device development as well as maturing applications, the 1996 O/E LASE conference program is diverse. "Recent developments in high-powered laser diodes are improving applications such as material processing, medical treatment, and applied spectroscopy," says Kurt Linden (Spire Corp., Bedford, MA), chair of the Laser Diode Applications II conference. A special session on laser-based fiber sensors touches on civil engineering applications and devices such as fiberoptic gyroscopes.
A high-power, self-pulsating aluminum gallium indium phosphide (AlGaInP) diode laser operating at 635 nm will be described by researchers from SDL Inc. (San Jose, CA; paper #2682-16). A session on diode lasers operating beyond 2 µm includes a talk on increasing the efficiency of AT&T`s quantum cascade laser by going to a two-well active region with vertical transition and Bragg electron confinement (paper #2682-28).
Detectors as well as sources are being developed for operation farther into both ends of the spectrum. "The Photodetector Materials and Devices conference will introduce the most recent developments from the ultraviolet to the far-infrared." says chair Erwan Bigan (Northwestern University, Evanston, IL). Lyn Brown of the Air Force Wright Laboratory (Wright Patterson AFB, OH) is slated to deliver a keynote address on the current state and future of infrared detector technology (paper #2685-01), and researchers from Northwestern will detail recent developments in ultraviolet detectors used in astrophysics (paper #2685-16).
The Functional Photonic Integrated Circuits conference touches on topics ranging from simulation to large scale integrated optics. Digital transmission systems using surface emitting lasers and photodetectors in integrated circuits are to be presented by AT&T Bell Laboratories personnel (Murray Hill, NJ; paper #2695B-32). Practical aspects of packaging photonic integrated circuits and optoelectronic components are discussed in a paper from Georgia Institute of Technology (Atlanta, GA; paper #2695B-48).
Solid-state laser developments are also a featured part of the O/E LASE program. "The field of femtosecond pulse generation continues to progress at a rapid pace, particularly in the areas of pulse amplification, shaping, and measurement," agree conference cochairs William White (Lawrence Livermore National Laboratory, Livermore, CA) and David Reitze (University of Florida, Gainesville, FL).
Breakthroughs in ultrashort (sub- 20 fs) pulse amplification using novel techniques to minimize gain narrowing and pulse dispersion in Ti:Sapphire are being reported by collaborators from University of California San Diego (La Jolla, CA) and Ecole Polytechnique ENSTA (France) (paper #2701-11). Progress in pulse amplification to above the 100 TW level will be reported by groups at Lawrence Livermore National Laboratory (Livermore, CA) (paper #2701-15) and CREOL, University of Central Florida (Orlando, FL) (paper #2701-12).
Complementing the technical sessions, Town Squares on the exhibit floor will feature several interesting applications of semiconductor lasers. A tunable diode laser manages process control in an applied spectroscopy system developed by groups from Focused Research (San Jose, CA) and Stanford University (Palo Alto, CA). Stanford researcher Elizabeth Downing will demonstrate a solid-state, three-dimensional display with wavelength addressable red-green-blue (RGB) color capabilities (see photo on p. 113).
Semiconductor device fabrication advancements using high-power lasers are addressed in a technical presentation by the National Research Council of Canada laser processing group (Ottawa, ON; paper #2703B-53). They discuss laser-assisted dry etching ablation of group III-V semiconductors, focusing on photoresist-free patterning of indium phosphide (InP) wafers for selective area epitaxy and formation of quantum dot structures. The resolution of the xenon chloride (XeCl) excimer laser assisted etching process is better than 20 nm. The direct formation of linear gratings with periods from 250 to 450 nm indicates the potential of this method in the fabrication of distributed feedback (DFB) laser structures.
In the Lasers and Optoelectronics Town Square, Dr. Axel Scherer of the California Institute of Technology (Pasadena, CA) will discuss developments in precision control of the spectral response and reflectivity of photonic crystals used in the fabrication of microlasers and high-speed optical interconnect devices. Such devices are suited for pumping optoelectronic devices and for directional coupling of light.
Electronic imaging science and technology
Numerous innovations presented in the EI S&T conference program impact applications ranging from security to manufacturing. Comments Optical Security and Counterfeit Deterrence Techniques conference chair Ruud van Renesse (TNO Institute of Applied Physics, Delft, the Netherlands), "Security tools to protect documents have steadily advanced, and this evolution of security features allows us to sculpture matter into diffractive and interference elements with nanometer precisions." These optical effects are difficult to counterfeit, easily verified, and yet are suitable for mass production; they will be incorporated in the first new design of the US dollar in more than 60 years (paper #2659-05).
Another widely applicable technology, machine vision, can greatly improve inspection and process control in high-volume, high-speed, or high-precision manufacturing such as integrated circuits, ceramics, textiles, paper, metals, and agriculture. An automatic vision system for textile surfaces by the Institut d`Ingenierie de la Vision (St. Etienne, France; paper #2665-12) and a three-dimensional system for noncontact dimensional inspection by the Rensselaer Polytechnic Institute (Troy, NY; paper #2665-19) are just two applications.
Data storage and retrieval
Several conferences consider the issues involved with displaying and analyzing large-scale data files. As Storage and Retrieval for Still Image and Video Databases IV conference chair Ishwar Sethi (Wayne State University, Detroit, MI) comments, "Because of the large-scale, ambiguous, and unstructured nature of visual and multimedia data, new and innovative methods are needed for modeling, organization, and indexing for efficient storage and retrieval." Ron Erbacher (University of Massachusetts, Lowell, MA), chair of the Visual Data Exploration and Analysis III conference, adds, "Vast amounts of data from satellites, medical resonance imagers, computer simulations, and other applications continue to be generated and archived. Techniques for assisting users in exploring and analyzing these large sets of data effectively with visualization methods are the focus of our conference."
The Imaging and Display Town Square will feature projection, stereoscopic, and high-resolution displays in multimedia and telemedicine applications. Virtual reality systems and head-mounted displays will be demonstrated by General Reality (San Jose, CA) a start-up company specializing in applied virtual reality systems.
The BiOS technical program is packed with conferences on medical applications of lasers, and clinical and biochemical instrumentation. Many papers apply the technologies discussed in the O/E LASE and EI S&T programs to real-world problems in medicine and medical research, and the BiOS Town Square will bring many features of the biomedical applications to life. More than 7600 people attended the first Photonics West last year; projected attendance for 1996 is even higher. n
FIGURE 1. Solid-state, three-dimensional display with wavelength-addressable red-green-blue (RGB) color capabilities is based on two-step, two-frequency upconversion in rare-earth-doped heavy metal fluoride glass.