Optics and photonics technologies are central to modern life; indeed, UNESCO has recently adopted a resolution declaring 2015 to be the International Year of Light.1 These technologies enable the manufacture and inspection of all the integrated circuits in every electronic device in use.2 They give us displays on our smartphones and computing devices, optical fiber that carries the information in the Internet, advanced precision fabrication, and medical diagnostics tools. Optics and photonics technology offers the potential for even greater societal impact over the next few decades. Solar power generation and new efficient lighting, for example, could transform the energy landscape, and new optical capabilities will be essential to supporting the continued exponential growth of the Internet. Optics and photonics technology development and applications have substantially increased across the globe over the past several years. This is an encouraging trend for the world’s economy and its people, while at the same time posing a challenge to U.S. leadership in these areas. As described in this study conducted by the National Research Council’s (NRC’s) Committee on Harnessing Light: Capitalizing on Optical Science Trends and Challenges for Future Research, it is critical that the United States take advantage of these emerging optical technologies for creating new industries and generating job growth.
2 For example, photolithography is used to create most of the layers in integrated circuits, and cameras inspect the quality afterward.
Each chapter of the present report addresses the developments that have taken place over the 15 years since the publication of the NRC report Harnessing Light: Optical Science and Engineering for the 21st Century,3 technological opportunities that have arisen since then, and the state of the art in the United States and abroad, and recommendations are offered for how to maintain U.S. global leadership.
It is the committee’s hope that this study will help policy makers and leaders decide on courses of action that can advance the economy of the United States, provide visionary guidance and support for the future development of optics and photonics technology and applications, and ensure a leadership role for the United States in these areas. Although many unknowns exist in the course of pursuing basic optical science and its transition to engineering and ultimately to products, the rewards can be great. Researchers have achieved some dramatic advances. For example, work in optics and photonics has now provided clocks so stable that they will slip less than 1 second in more than 100 million years. Much more primitive clocks enabled the incredibly useful Global Positioning System (GPS), and it remains to be discovered how these new clock advances can be fully harnessed for the benefit of society. In many ways, the current period might be analogous to the dawn of the laser in 1960, when many of the transforming applications of that extraordinary invention had not yet been contemplated. This is only one example of technology innovation in optics and photonics that can lead to future major applications.
GRAND CHALLENGE QUESTIONS TO FILL TECHNOLOGICAL GAPS
To fill identified technological gaps in pursuit of national needs and national competitiveness, the committee developed five overarching grand challenge questions:
1. How can the U.S. optics and photonics community invent technologies for the next factor-of-100 cost-effective capacity increases in optical networks?
As mentioned in Chapter 3, it is not currently known how to achieve this goal, but the world has experienced a factor-of-100 cost-effective capacity increase every decade thus far, and user demand for this growth is anticipated to continue. Unfortunately, the mechanisms that have enabled the previous gains cannot sustain further increases at that high rate, and so the world will either see increases in capability stagnate or will have to invent new technologies.
3 National Research Council. 1998. Harnessing Light: Optical Science and Engineering for the 21st Century. Washington, D.C.: National Academy Press.
2. How can the U.S. optics and photonics community develop a seamless integration of photonics and electronics components as a mainstream platform for low-cost fabrication and packaging of systems on a chip for communications, sensing, medical, energy, and defense applications?
In concert with meeting the fifth grand challenge, achieving this grand challenge would make it possible to stay on a Moore’s law-like path of exponential performance growth. The seamless integration of optics and photonics at the chip level has the potential to significantly increase speed and capacity for many applications that currently use only electronics, or that integrate electronics and photonics at a larger component level. Chip-level integration will reduce weight and increase speed while reducing cost, thus opening up a large set of future possibilities as devices become further miniaturized.
3. How can the U.S. military develop the required optical technologies to support platforms capable of wide-area surveillance, object identification and improved image resolution, high-bandwidth free-space communication, laser strike, and defense against missiles?
Optics and photonics technologies used synergistically for a laser strike fighter or a high-altitude platform can provide comprehensive knowledge over an area, the communications links to download that information, an ability to strike targets at the speed of light, and the ability to robustly defend against missile attack. Clearly this technological opportunity could act as a focal point for several of the areas in optics and photonics (such as camera development, high-powered lasers, free-space communication, and many more) in which the United States must be a leader in order to maintain national security.
4. How can U.S. energy stakeholders achieve cost parity across the nation’s electric grid for solar power versus new fossil-fuel-powered electric plants by the year 2020?
The impact on U.S. and world economies from being able to answer this question would be substantial. Imagine what could be done with a renewable energy source, with minimal environmental impact, that is more cost-effective than nonrenewable alternatives. Although this is an ambitious goal, the committee poses it as a grand challenge question, something requiring an extra effort to achieve. Today, it is not known how to achieve this cost parity with current solar cell technologies.
5. How can the U.S. optics and photonics community develop optical sources and imaging tools to support an order of magnitude or more of increased resolution in manufacturing?
Meeting this grand challenge could facilitate a decrease in design rules for lithography, as well as providing the ability to do closed-loop, automated manufacturing of optical elements in three dimensions. Extreme ultraviolet (EUV) is a challenging technology to develop, but it is needed in order to meet future lithography needs. The next step beyond EUV is to move to soft x rays. Also, the limitations in three-dimensional resolution on laser sintering for three-dimensional manufacturing are based on the wavelength of the lasers used. Shorter wavelengths will move the state of the art to allow more precise additive manufacturing that could eventually lead to three-dimensional printing of optical elements.
The committee believes that these five grand challenges are the top priorities in their respective application areas, and that because of their diverse nature, further prioritization among them is not advisable. These grand challenge questions are discussed in the main text immediately after the first key recommendation that supports the challenge and are drawn from the findings and recommendations throughout the report. They are discussed in the chapter in which they first appear, and occasionally in succeeding chapters.
REPORT CONTENT AND KEY RECOMMENDATIONS
This report is divided into chapters based on application areas, with crosscutting chapters addressing the impact of photonics on the national economy, advanced manufacturing, and strategic materials. Following an introductory Chapter 1, Chapter 2 discusses the impacts of photonics technologies on the U.S. economy.
Chapters 3 through 10 each cover a particular area of technological application. As mentioned, the discussion of each application area typically begins with a review of updates in the state of the science since the publication of the NRC’s report Harnessing Light, as well as the technological opportunities that have arisen from recent advances in and potential applications of optical science and engineering. Included are recommended actions for the development and maintenance of global leadership in the photonics-driven industry, including both near-term and long-range goals, likely participants, and responsible agents of change. As relevant to their respective topics, the chapters assess the current state of optical science and engineering in the United States and abroad, including trends in private and public research, market needs, examples of translating progress in photonics innovation into global competitive advantage (including activities by small businesses), workforce needs, manufacturing infrastructure, and the impact of photonics on the national economy.
Chapter 2: Impact of Photonics on the National Economy
Chapter 2 considers the economic impact of optics and photonics on the nation and the world. This chapter uses a case study of lasers to discuss the conceptual challenges of developing estimates of the economic impact of photonics innovation. It also addresses the problems associated with using company-level data to provide indicators of the economic significance of the “photonics sector” within the U.S. economy. Additionally, this chapter discusses the ways in which the changing structure of the innovation process within photonics reflects broader shifts in the sources of innovation within the U.S. economy. The chapter also considers the results of recent experiments in public-private and inter-firm research and development (R&D) collaboration in other high-technology areas for the photonics sector. Possibly the most important finding of the committee in this area is related to the pervasive nature of optics and photonics as an enabling technology.
Key Recommendation: The committee recommends that the federal government develop an integrated initiative in photonics (similar in many respects to the National Nanotechnology Initiative) that seeks to bring together academic, industrial, and government researchers, managers, and policy makers to develop a more integrated approach to managing industrial and government photonics R&D spending and related investments.
This recommendation is based on the committee’s judgment that the photonics field is experiencing rapid technical progress and rapidly expanding applications that span a growing range of technologies, markets, and industries. Indeed, in spite of the maturity of some of the constituent elements of photonics (e.g., optics), the committee believes that the field as a whole is likely to experience a period of growth in opportunities and applications that more nearly resembles what might be expected of a vibrantly young technology. But the sheer breadth of these applications and technologies has impeded the formulation by both government and industry of coherent strategies for technology development and deployment.
A national photonics initiative would identify critical technical priorities for long-term federal R&D funding. In addition to offering a basis for coordinating federal spending across agencies, such an initiative could provide matching funds for industry-led research consortia (of users, producers, and material and equipment suppliers) focused on specific applications, such as those described in Chapter 3 of this report. In light of near-term pressures to limit the growth of or even
reduce federal R&D spending, the committee believes that a coordinated initiative in photonics is especially important.
The committee assesses as deplorable the state of data collection and analysis of photonics R&D spending, photonics employment, and sales. The development of better historical and current data collection and analysis is another task for which a national photonics initiative is well suited.
Key Recommendation: The committee recommends that the proposed national photonics initiative spearhead a collaborative effort to improve the collection and reporting of R&D and economic data on the optics and photonics sector, including the development of a set of North American Industry Classification System (NAICS) codes that cover photonics; the collection of data on employment, output, and privately funded R&D in photonics; and the reporting of federal photonics-related R&D investment for all federal agencies and programs.
It is essential that an initiative such as the proposed national photonics initiative be supported by coordinated measurement of the inputs and outputs in the sector such that national policy in the area can be informed by the technical and economic realities on the ground in the nation.
Chapter 3: Communications, Information Processing, and Data Storage
Chapter 3 considers communications, information processing, and data storage. The Internet’s growth has fundamentally changed how business is done and how people interact. Photonics has been a key enabler allowing this communication revolution to occur. The committee anticipates that this revolution will continue, with additional demands driving significant increases in bandwidth and an even heavier reliance on the Internet. So far there has been a factor-of-100 increase in capacity each decade. However, there exists a technology wall inhibiting achievement of the next factor-of-100 growth.
Key Recommendation: The U.S. government and private industry, in combination with academia, need to invent technologies for the next factor-of-100 cost-effective capacity increase in long-haul, metropolitan, and local-area optical networks.
The optics and photonics community needs to inform funding agencies, and information and entertainment providers, about the looming roadblock that will interfere with meeting the growing needs for network capacity and flexibility. There
is a need to champion collaborative efforts, including consortia of companies, to find new technology—transmission, amplification, and switching—to carry and route at least another factor-of-100 capacity in information over the next 10 years.
Key Recommendation: The U.S. government, and specifically the Department of Defense (DOD), should strive toward harmonizing optics with silicon-based electronics to provide a new, readily accessible and usable, integrated electronics and optics platform.
They should also support and sustain U.S. technology transition toward low-cost, high-volume circuits and systems that utilize the best of optics and electronics in order to enable integrated systems to seamlessly provide solutions in communications, information processing, biomedical, sensing, defense, and security applications. Government funding agencies, the Department of Defense, and possibly a consortium of companies requiring these technologies should work together to implement this recommendation. This technology is one approach to assist in accomplishing the first key recommendation in Chapter 3 concerning the factor-of-100 increase in Internet capability.
Key Recommendation: The U.S. government and private industry should position the United States as a leader in the optical technology for the global data center business.
Optical connections within and between data centers will be increasingly important in allowing data centers to scale in capacity. The committee believes that strong partnering between users, content providers, and network providers, as well as between businesses, government, and university researchers, is needed for ensuring that the necessary optical technology is generated, which will support continued U.S. leadership in the data center business.
Chapter 4: Defense and National Security
In Chapter 4, the committee discusses defense and national security. It is becoming increasingly clear that sensor systems are the next “battleground” for dominance in intelligence, surveillance, and reconnaissance. Comprehensive knowledge across an area will be a great defense advantage, along with the ability to communicate information at high bandwidths and from mobile platforms. Laser weapon attack can provide a significant advantage to U.S. forces. Defense against missile attacks, especially ballistic missiles, is another significant security need. Optical systems can provide synergistic capability in all these areas.
Key Recommendation: The U.S. defense and intelligence agencies should fund the development of optical technologies to support future optical systems capable of wide-area surveillance, exquisite long-range object identification, high-bandwidth free-space laser communication, “speed-of-light” laser strike, and defense against both missile seekers and ballistic missiles. Practical application for these purposes would require the deployment of low-cost platforms supporting long dwell times.
These combined functions will leverage the advances that have been made in high-powered lasers, multi-function sensors, optical aperture scaling, and algorithms that exploit new sensor capabilities, by bringing the developments together synergistically. These areas have been pursued primarily as separate technical fields, but it is recommended that they be pursued together to gain synergy. One method of maintaining this coordination could include reviewing the coordination efforts among agencies on a regular basis.
Chapter 5: Energy
Chapter 5 deals with optics and photonics in the energy area. Both the generation of energy and the efficient use of energy are discussed in terms of critical national needs. Photonics can provide renewable solar energy, while solid-state lighting can help reduce the overall need for energy used for lighting.
Key Recommendation: The Department of Energy (DOE) should develop a plan for grid parity across the United States by 2020.
“Grid parity” is defined here as the situation in which any power source is no more expensive to use than power from the electric grid. Solar power electric plants should be as cheap, without subsidies, as alternatives. It is understood that this will be more difficult in New England than in the southwestern United States, but the DOE should strive for grid parity in both locations.
Even though significant progress is being made toward reducing the cost of solar energy, it is important that the United States bring the cost of solar energy down to the price of other current alternatives without subsidy and maintains a significant U.S. role in developing and manufacturing solar energy alternatives. There is a need not only for affordable renewable energy but also for creating jobs in the United States. A focus in this area can contribute to both. Lowering the cost of solar cell technology will involve both technology and manufacturing advances.
Solid-state lighting can also contribute to energy security in the United States.
Key Recommendation: The DOE should strongly encourage the development of highly efficient light-emitting diodes (LEDs) for general-purpose lighting and other applications.
For example, the DOE could move aggressively toward its 21st-century lightbulb, with greater than 150 lm/W, a color rendering index greater than 90, and a color temperature of approximately 2800 K. Since one major company has already published results meeting the technical requirements for the 21st-century lightbulb, the DOE should consider releasing this competition in 2012. Major progress is being made in solid-state lighting, which has such advantages over current lighting alternatives as less wasted heat generation and fast turn-on time. The United States needs to exploit the current expertise in solid-state lighting to bring this technology to maturity and to market.
Chapter 6: Health and Medicine
Chapter 6 discusses the application of optics and photonics to health and medicine. Photonics plays a major role in many health-related areas. Medical imaging, which is widely used and is still a rapidly developing area, is key to many health-related needs, both for gaining understanding of the status of a patient and for guiding and implementing corrective procedures. Lasers are used in various corrective procedures in addition to those for the eye. There is still great potential for further application of optics and photonics in medicine.
Key Recommendation: The U.S. optics and photonics community should develop new instrumentation to allow simultaneous measurement of all immune-system cell types in a blood sample. Many health issues could be addressed by an improved knowledge of the immune system, which represents one of the major areas requiring better understanding.
Key Recommendation: New approaches, or dramatic improvements in existing methods and instruments, should be developed by industry and academia to increase the rate at which new pharmaceuticals can be safely developed and proved effective. Developing these approaches will require investment by the government and the private sector in optical methods integrated with high-speed sample-handling robotics, methods for evaluating the molecular makeup of microscopic samples, and increased sensitivity and specificity for detecting antibodies, enzymes, and important cell phenotypes.
Chapter 7: Advanced Manufacturing
Chapter 7 addresses the field of advanced manufacturing and the way in which it relates to optics and photonics. Advanced manufacturing is critical for the economic well-being of the United States. While there are issues concerning the ability of the United States to compete successfully in high-volume, low-cost manufacturing, it is likely that the United States can continue to be a strong competitor in lower-volume, high-end manufacturing. Additive manufacturing has the potential to allow the production of parts near the end user no matter where the design is done. Thus, if the end user is in the United States, it is there that the printing or manufacturing would occur. Optical approaches, such as laser sintering, are very important approaches to three-dimensional printing.
Key Recommendation: The United States should aggressively develop additive manufacturing technology and implementation.
Current developments in the area of lower-volume, high-end manufacturing include, for example, three-dimensional printing, also called additive manufacturing. With continued improvements in the tolerance and surface finish, additive manufacturing has the potential for substantial growth. The technology also has the potential to allow three-dimensional printing near the end user no matter where the design is done.
Key Recommendation: The U.S. government, in concert with industry and academia, should develop soft x-ray light sources and imaging for lithography and three-dimensional manufacturing.
Advances in table-top sources for soft x rays will have a profound impact on lithography and optically based manufacturing. Therefore, investment in these fields should increase to capture intellectual property and maintain a leadership role for these applications.
Chapter 8: Advanced Photonic Measurements and Applications
Chapter 8 discusses sensing, imaging, and metrology in relation to optics and photonics. Sensing, imaging, and metrology have made significant progress since the publication of the NRC’s Harnessing Light in 1998.4 Notable developments include having at least one Nobel Prize awarded for developing dramatic increases in
4 National Research Council. 1998. Harnessing Light: Optical Science and Engineering for the 21st Century. Washington, D.C.: National Academy Press.
the precision of time measurement.5 Single-photon detectors have been developed, but at this time they are only available with a dead time after detection, not allowing single-photon sensitivity for detecting all incoming photons. Extreme nonlinear optics has made significant progress, providing the potential for soft x-ray sources and imaging. Entangled photons and squeezed states are new areas for R&D in the optics and photonics field, allowing sensing options never previously considered.
Key Recommendation: The United States should develop the technology for generating light beams whose photonic structure has been prearranged to yield better performance in applications than is possible with ordinary laser light.
Prearranged photonic structures in this context include generation of light with specified quantum states in a given spatiotemporal region, such as squeezed states with greater than 20-dB measured squeezing in one field quadrature, Fock states of more than 10 photons, and states of one and only one photon or two and only two entangled photons with greater than 99 percent probability. These capabilities should be developed with the capacity to detect light with over 99 percent efficiency and with photon-number resolution in various bands of the optical spectrum. The developed devices should operate at room temperature and be compatible with speeds prevalent in state-of-the-art sensing, imaging, and metrology systems. U.S. funding agencies should give high priority to funding research and development—at universities and in national laboratories where such research is carried out—in this fundamental field to position the U.S. science and technology base at the forefront of applications development in sensing, imaging, and metrology. It is believed that this field, if successfully developed, can transfer significant technology to products for decades to come.
Key Recommendation: Small U.S. companies should be encouraged and supported by the government to address market opportunities for applying research advances to niche markets while exploiting high-volume consumer components. These markets can lead to significant expansion of U.S.-based jobs while capitalizing on U.S.-based research.
Chapter 9: Strategic Materials for Optics
Chapter 9 deals with strategic materials for optics. The main developments in materials for optics and photonics are the emergence of metamaterials and the
5 For example, the 2005 Nobel Prize in physics. More information can be found at http://www.nobelprize.org/nobel_prizes/physics/laureates/2005/. Accessed August 2, 2012.
realization of how vulnerable the United States is to the need for certain critical materials. At this time, some of those materials are available only from China.
Recommendation: The U.S. R&D community should increase its leadership role in the development of nanostructured materials with designable and tailorable optical material properties, as well as process control for uniformity of production of these materials.
Chapter 10: Displays
Chapter 10 addresses display technology. The major current display industry is based on technologies invented primarily in the United States, but this industry’s manufacturing operations are located mostly overseas. Labor costs were a consideration, but other factors such as the availability of capital were significant in creating this situation. However, the United States is still dominant in many of the newer display technologies, and it still has an opportunity to maintain a presence in those newer markets as they develop.
Recommendation: U.S. private companies and the Department of Defense should ensure a leadership role by funding R&D related to new materials for flexible, low-power, holographic and three-dimensional display technologies.
In reviewing the technologies considered here, a number of potential future opportunities have come to light that allow one to imagine changes to daily life: for example, electronic imaging devices implantable in the eye which can restore sight to the blind; cost-effective, laser-based, three-dimensional desktop printing of many different types of objects; the generation, detection, and manipulation of single photons in the same way as is done with single electrons, and doing it all on a photonic integrated circuit; the use of optics as interconnects between integrated circuit chips, with dramatic increases in power efficiency and speed; the unfurling of a flexible display on a smartphone or the watching of holographic images at home; and the ability of mobile lasers to neutralize threats from afar with high accuracy and speed. These are just a few interesting examples of potential changes that can occur as a result of the enabling technologies considered in this study.