Harnessing Light Optical Science and Engineering for the 21st Century (1998) / Chapter Skim
Currently Skimming:
7 Optics Research and Education
7 Optics Research and Education
Pages 275-318
The Chapter Skim interface presents what we've algorithmically identified as the most significant single chunk of text within every page in the chapter.
Select key terms on the right to highlight them within pages of the chapter.
From page 275... ...
The first part of this chapter highlights some examples of research areas that hold special promise for further discoveries. This is a time of great excitement for all optics researchers, whether in uni varsities, industry, or government laboratories.
|
From page 276... ...
The most important discoveries often arise at boundaries between established fields in the case of the laser, at the interface between physics and electrical engineering. The ultimate impact of research is rarely predictable.
|
From page 277... ...
in 1995 announced a multidisciplinary research initiative in optical science and engineering. The program attracted more than 600 pre-proposals and 70 full proposals.
|
From page 278... ...
. Today, work at the interface of physics and electrical engineering is a key element of optics research, producing such important develop ments as the semiconductor diode laser.
|
From page 279... ...
Femtosecond laser technology and its application to ultrafast physics, chemistry, and engineering is identified as a particularly promising opportunity. Advanced laser sources and frequency conversion of lasers using nonlinear optical devices offer significant potential for applications in semiconductor processing, reprographics, and image display.
|
From page 280... ...
Quantum, Atomic, and Biological Optics Contro' of Atoms by Light Light continues to be the principal method of probing matter. Powerful spectroscopic techniques continue to be developed as light sources extend into new regimes of the electromagnetic spectrum and as optical sources with extremely short pulses such as femtosecond lasers, synchrotron sources, and free electron lasers become more widely used.
|
From page 281... ...
, the atomic energy is distributed in all directions equally among the many occupied quantum states, in accord with the principles of statistical physics. As the threshold condition is crossed (center)
|
From page 282... ...
Quantum mechanics defines the fundamental noise floor. For example, the uncertainty principle tells us that the simultaneous measurement of position and momentum with uncertainties lax and lop is limited to an accuracy l~xl~p 2 h, where h is Planck's constant.
|
From page 283... ...
Unlike a classical computer based on irreversible, dissipative transitions between distinct states such as 0 and 1, a quantum computer based on the reversible quantum evolution of linear superpositions of quantum states could in principle greatly reduce the time needed to solve certain problems. For example, on a conventional computer the time required to determine a number's prime factors (a problem with important applications in cryptography)
|
From page 284... ...
Two-photon excitation from inexpensive diode-pumped femtosecond lasers will permit the observation of the intrinsicfluorescence of biological molecules and molecules in the interior of tissues that could not otherwise be detected. Fluorescent dyes can also be used to monitor their local biological environment since the fluorescence is affected by conditions such as temperature, electric fields, and pH.
|
From page 285... ...
Just as powerful new insights have come from the study of single, isolated quantum systems, the study of biology at the level of a single molecular event will undoubted Iy reveal unexpected behavior. The National Science Foundation should recognize the dramatic new opportunities in fundamental research in atomic, molecular, and quantum optics and should encourage support for research in these areas.
|
From page 286... ...
capture the full bandwidth of optics coherently. Thus, they can be sculpted by frequency-domain methods to produce the unique optical waveforms required to manipulate selected quantum states of atoms and molecules.
|
From page 287... ...
Further exciting developments can be expected during the next decade, including laser acceleration and laser-driven inertial confinement fusion. Intense femtosecond pulses have also been found to have some dramatic advantages in materials processing.
|
From page 288... ...
Technology of Femtosecond Lasers The current rapid advance in femtosecond technology is made possible by recently invented methods for ultrashort pulse generation with solid-state lasers. Early pioneering work with dye lasers opened the femtosecond time domain to science and laid many of the foundations for present technological advances.
|
From page 289... ...
Technology Applications To date, the principal beneficiaries of developments in femtosecond technology have been scientific applications, but the prospect of compact, practical, cost-effective femtosecond laser sources is now creating opportunities for a variety of mainstream commercial applications. Some take direct advantage of the ultrahigh-speed aspect of the technology.
|
From page 290... ...
, ultrahigh-rate data processing, and clock distribution. Femtosecond laser sources with high peak and average power open the possibility of using a laser to accelerate electrons in place of the microwave source traditionally used for this application.
|
From page 291... ...
Semiconductor and Advanced So~id-State Lasers Lasers are now essential to the national economy, enabling applications that extend from CD-ROM to the fiber information network; from the processing and fabrication of semiconductors to the cutting of cloth, plastic, and industrial materials; and from laser vision correction to theraputic medicine. Laser sources have made a transition from the gas discharge tubes associated with the ubiquitous red hel ium-neon lasers used in supermarket scanners and the blue-green argon ion lasers familiar in laser light shows to solid-state laser diodes (LDs)
|
From page 292... ...
Worldwide laser diode sales in 1 996 were $1 .92 bil lion. The worldwide market for all laser sources was $2.82 billion.
|
From page 293... ...
A similar time might be required before blue laser diodes are available commercially. When introduced as a product, the blue laser diode will open major application areas including information storage and optical displays.
|
From page 294... ...
Laser d lodes coupled to optical fibers enable direct processing of materials through cutting, welding, and annealing. High-power laser diode arrays are also widely used today to pump advanced solid-state laser sources.
|
From page 295... ...
Further, reliability is improved from the 200-hour lifetime of lamps to the greater than 7,000-hour lifetime for laser diodes. These factors, coupled with the small size of the DPSSL, have opened new areas of application in reprographics and medicine and have extended earlier applications in laser radar, remote sensing, semiconductor processing, and industrial materials processing such as welding, cutting, and surface hardening.
|
From page 296... ...
These projects serve as grand challenges for the coming decade and will drive the performance of laser sources. The Laser Interferometer GravitationalWave Observatory (LIGO)
|
From page 297... ...
In the future, DPSSLs may provide the 10 M] of energy at the required 1 00-MW average power for the generation of electricity using the laser-driven inertial confinement fusion process.
|
From page 298... ...
Solid-state lasers of commercial importance are the semiconductor laser diodes and the Nd:YAG sol id-state laser. The difficu Ity and the cost of inventing and developing laser systems that operate at new wavelengths makes it important to extend existing well-developed lasers to new wavelengths by nonlinear frequency conversion.
|
From page 299... ...
opened the ultraviolet wavelength region where there are important applications such as UV lithography, CD master production, and materials processing by laser ablation. To be of commercial interest, nonlinear crystals must meet the physical requirements of adequate nonlinear coefficient, good optical quality and transparency, ease of growth and fabrication, and chemical stabi I ity.
|
From page 300... ...
Continued investments are necessary to extend our knowledge and to maintain our technology lead. Future applications of nonlinear crystal chips may include the frequency doubling of laser diodes to generate blue radiation for information storage.
|
From page 301... ...
Quantum wells are used to engineer the density of states of semiconductor diode lasers to provide both higher gain and wavelength control. Most laser diodes, and especially high-power laser diodes, are constructed by the use of quantum wells to control the electron states.
|
From page 302... ...
The materials processing challenges are great, but so is the payoff if photonic bandgap crystals can be realized. Materials for Shaping and Focusing Optical Radiation Lenses have been important in the development of optical devices and other technologies for centuries.
|
From page 303... ...
Materials Research and Development Opportunities Research opportunities in lasers and engineered optical devices that offer significant leverage for research investment are based often on a better understanding and control of materials (Box 7.9~. In laser diode sources, progress in the understanding and synthesis of III-V semiconductor materials will enable new laser diodes and blue laser diodes.
|
From page 304... ...
The committee recommends that the Defense Advanced Research Projects Agency (DARPA) coordinate and invest in research on new optical materials and materials processing methods with the goal of achieving breakthrough capability through engineered semiconductor, dielectric, and nonlinear optical materials.
|
From page 305... ...
Such predictions spurred a prodigious effort in materials research, especially in the area of materials processing, resting heavily on a knowledge of chemical thermodynamics, kinetics, gas dynamics, and polymer science. By 1980 the best fibers were so transparent that a signal could pass through 150 miles of fiber before becoming too weak to detect.
|
From page 306... ...
FIGURE7.10 X-raymicroscope images of a red blood cell show features of a malaria infection site observed at a resolution not obtainable with an optical microscope. Theleftimage shows a new infection.
|
From page 307... ...
For example, an industrial consortium has been formed to invest $200 million in the development of EUV lithography. One promising approach with research under way in the United States, Japan, and Europe is to use high peak and average power solid-state lasers to generate a laser-produced plasma that radiates EUV and x-ray output.
|
From page 308... ...
Multiple agencies with interest in the crosscutting science and technology of EUV and soft x-ray optics and techniques should encourage research in this area because of the substantial potential economic payback in the near future. Education in Optics Formal university-level education in optics started in the United States in 1927, after considerable national debate.
|
From page 309... ...
Two major guides are produced by the professional societies. The most recent is Optics Education 1996: Annua/ Guide to Optics Programs Worldwide, produced by the I International Society for Optical Engi neeri ng (SPI E)
|
From page 310... ...
The professional societies should evaluate educational programs in optics and jointly produce an annual guide. Because of the strong correlation between education and scholarly publishing, the major optics research journals are useful indicators of optics education, especially when comparing the level of activity in different countries.
|
From page 311... ...
Universities should encourage multidisciplinarity in optics education, cutting across departmental boundaries, and should provide research opportunities at all levels, from the bachelor of science to the doctorate and from basic science to applied technology. These diverse optics programs are sufficient to meet current needs and probably also have the capacity and flexibility to meet future needs.
|
From page 312... ...
Issues Research in optics cuts across disciplinary boundaries and enables advances in many other areas of research as well as commercial applications that are important for the nation's future growth and prosperity. As indicated by the response to the NSF optical science and engineering initiative in 1995, there is high demand and strong competition for optics research funding.
|
From page 313... ...
The disturbance of the quantum variable of interest can be minimized by shifting the effect of the measurement to another quantum degree of freedom. Quantum states with several degrees of freedom can be engineered so that the quantum phase of the entire system can be preserved.
|
From page 314... ...
Laser acceleration benefits from the high peak power of focused femtosecond lasers. Terahertz imaging and optical coherence tomography (see Chapter 2)
|
From page 315... ...
Light-emitting diodes are lower in power and efficiency than laser diodes, but their very low cost enables appl ications in markets that exceed $3 hi l l ion. Organic and porous silicon-based LEDs offer the promise of a low-cost, paper-like display that can be addressed by a pocket-sized opticalbased information storage unit.
|
From page 316... ...
Progress in materials science and engineering is critical to progress in optics. The committee recommends that DARPA coordinate and invest in research on new optical materials and materials processing methods with the goal of achieving breakthrough capability though engineered semiconductor, dielectric, and nonlinear optical materials.
|
From page 317... ...
NSF should develop an agency-wide, separately funded initiative to support multidisciplinary research and education in optics. Opportunities include fundamental research in atomic, molecular, and quantum optics; femtosecond optics, sources, and applications; solidstate laser sources and applications; and EUV and soft x-ray optics.
|
From page 318... ...
SPI E.1996. Optics Education 1996: Annua/ Guide to Optics Programs Worldwide.
|
Key Terms
This material may be derived from roughly machine-read images, and so is provided only to facilitate research.
More
information on Chapter Skim is available.