INVITED PAPER Optics and Photonics: Key Enabling Technologies This paper reviews the past, present, and future vision of the technologies of optics and photonics, including lasers, materials and devices, communications, bioimaging, displays, manufacturing, as well as the evolution of the photonics industry. By Alan E. Willner, Fellow IEEE, Robert L. Byer, Life Fellow IEEE, Constance J. Chang-Hasnain, Fellow IEEE, Stephen R. Forrest, Fellow IEEE, Henry Kressel, Life Fellow IEEE, Herwig Kogelnik, Life Fellow IEEE, Guillermo J. Tearney, Charles H. Townes, Life Fellow IEEE, and Michalis N. Zervas ABSTRACT | The fields of optics and photonics have experi- I. INTRODUCTION enced dramatic technical advances over the past several The phrase Boptics and photonics[ is used in the title be- decades and have cemented themselves as key enabling cause of the dual, powerful nature of light. It can be technologies across many different industries. This paper viewed: 1) as a propagating wave, like a radio wave, except explores past milestones, present state of the art, and future that the frequency of the wave is a million times higher perspectives of several different topics, including: lasers, (e.g., 200 THz); and 2) as a collection of traveling particles materials, devices, communications, bioimaging, displays, called photons, with similarities to the field of electronics manufacturing, and industry evolution. [1, 2]. The impact of advanced light technology on our society KEYWORDS | Communications; devices; displays; imaging; is still evolving, with the invention and first demonstration lasers; manufacturing; materials; optics; photonics of the laser being roughly 50 years ago [3, 4] and an even greater impact coming in the next few decades. Future opportunities abound for photonics-enabled advances in many fields. The laser provides a source of light that can be both: 1) coherent, meaning that a group of photons can act as a single unit; and 2) monochromatic, meaning that the photons can have a well-defined single color. With laser Manuscript received January 29, 2012; accepted February 7, 2012. Date of current version May 10, 2012. light: A. E. Willner is with the Department of Electrical Engineering, 1) high amounts of energy can be precisely directed University of Southern California, Los Angeles, CA 90089-2565 USA (e-mail: [email protected]). with low loss; R. L. Byer is with the E. L. Ginzton Laboratory, Stanford University, Stanford, 2) many different wave properties (i.e., degrees of CA 94305-4088 USA (e-mail: [email protected]). C. J. Chang-Hasnain is with the Electrical Engineering and Computer Science freedom such as amplitude, frequency, phase, Department, University of California Berkeley, Berkeley, CA 94720-1770 USA polarization, and direction) can be accurately (e-mail: [email protected]). S. R. Forrest is with the Office of the Vice President for Research, manipulated; University of Michigan, Ann Arbor, MI 48109-1340 USA (e-mail: [email protected]). 3) waves can be coherently processed to have high H. Kressel is with Warburg Pincus LLC, New York, NY 10017 USA. H. Kogelnik is with Bell Labs, Alcatel-Lucent, Holmdel, NJ 07733-0400 USA accuracy, speed, and dynamic range. (e-mail: [email protected]). These basic qualities and the technical advances in the G. J. Tearney is with Harvard Medical School, Cambridge, MA 02138 USA (e-mail: [email protected]). field of optics and photonics have enabled dramatic per- C. H. Townes is with The Graduate School, University of California Berkeley, formance enhancements across many different application Berkeley, CA 94720-1770 USA (e-mail: [email protected]). M. N. Zervas is with the Optoelectronics Research Centre, University of Southampton, areas. Southampton, Hampshire SO17 1BJ, U.K. (e-mail: [email protected]). Dramatic advances in optics and photonics technolo- Digital Object Identifier: 10.1109/JPROC.2012.2190174 gies have already had a major impact on daily life. For 1604 Proceedings of the IEEE |Vol.100,May13th,2012 0018-9219/$31.00 Ó2012 IEEE Willner et al.: Optics and Photonics: Key Enabling Technologies example, the IEEE/OSA Journal of Lightwave Tech- nology is cosponsored by seven different IEEE societies. The fields of optics and photonics are extremely broad in terms of technical topics and application areas. This paper tries to capture the excitement of the past, present, and future vision of these fields. While it is inevitable that we have overlooked key areas of these fields, we have tried in earnest to highlight some areas we thought could represent the advances enabled by our field. This paper is divided into several different subsections, namely: 1) overarching perspective; 2) lasers; 3) materials and devices; 4) communications; 5) bioimaging; 6) displays; 7) manufacturing; 8) evolution of the photonics industry. Fig. 1. Examples of application sectors that optics and photonics have significantly impacted for the time frame 2009–2010 [6]. In keeping with the spirit of the Centennial Special Issue of the Proceedings of the IEEE, each section is divided further into the following subsections: 1) introduction: context and importance of the topic; example, advances in optical fiber communications have 2) past: key past milestones and perspectives; enabled the amount of information that can be transmitted 3) present: state of the art and current thinking; from place to place to increase by nearly 100-fold over a 4) future: speculative vision. ten-year period, enabling a society-transforming Internet To those people who are interested in topics that we to thrive. Indeed, the current global internet itself would have neglected or whose pioneering work was not re- notexistwithoutoptics. ferenced in this paper, we offer our sincerest apologies. Over the past several decades, optics and photonics Such a large topic deserves more than just a few journal have experienced dramatic technical advances and have pages, but we hope to whet the reader’s appetite for the cemented themselves as key enabling technologies for a further information that can be found in the abundant myriad of industries. As a small anecdotal indication in the open literature. popular press of the breadth and depth of the field, roughly 12 out of the 50 best inventions of 2011 listed by Time Magazine had optics as a key technological ingredient of II. OVERARCHING PERSPECTIVE the invention [5]. Over the last two centuries, striking increases in human We can illustrate the Benabling[ impact that optics and science and technology have occurred, with light waves photonics have made on society by considering not only the being one of the important areas. direct value of the laser market itself but also the markets in By 1910, the concept of light quanta, i.e., the photon, which those lasers play an indispensible role in vibrant was beginning to be well-recognized by scientists. High- market growth. For example, Baer and Schlachter reported quality optical mirrors and lenses were being built, with that for the time frame 2009–2010, the following sectors Mt. Wilson’s 100-inch telescope being one of the striking were significantly impacted (see Fig. 1): 1) the $1 trillion examples then under way. Spectroscopy was, of course, transportation sector had a laser market of $1.3 billion, important, with increasing resolution and sensitivity. 2) the $2.5 trillion biomedical sector had a laser market There was as yet no radar, but radiowaves, particularly at of $400 million, and 3) the $4 trillion telecom, e-commerce long wavelengths, were being used. The theoretical rela- and IT sectors had a laser market of $3.2 billion [6]. tion of radiowaves to optical waves was recognized, al- Nearly 50 years ago, the IEEE integrated much of the though the technologies involved in transmitting and technical work of optics and photonics into the Quantum detecting light and radiowaves were very different. Electronics and Applications Council. Roughly 12 years Today, we have microwaves down to wavelengths of later, this council became the Quantum Electronics and less than a centimeter, and the explosion of work on lasers Applications Society, later being called the Lasers and has provided a wide variety of light sources, making light as Electro-Optics Society and now the Photonics Society. well as radio science and technology quite parallel and Although the Photonics Society is a hub of activity, the remarkably similar. The notion of quantized particles is, of multidisciplinary nature of our field is such that optics and course, now quite well accepted throughout the entire photonics play a key role in many IEEE societies. For electromagnetic spectrum. Lasers produce high intensities, Vol. 100, May 13th, 2012 | Proceedings of the IEEE 1605 Willner et al.: Optics and Photonics: Key Enabling Technologies very pure frequencies, excellent directivity, and very short was extended by five orders of magnitude to the visible pulses. A remarkable concentration of power can provide spectral region, and the potential of the laser for light-based enormous effective temperatures, and perhaps power weapons caught the public imagination. A new term entered densities large enough to generate atomic particles, e.g., into language that was soon to become ubiquitous: laser. energy. The ability of lasers to amplify and control light By 1964, many types of lasers had been invented, in- now makes the use of light and radiowaves much more cluding the helium neon laser [12], the diode laser [13], the similar than before; all electromagnetic waves are more CO2 laser [14], the mercury ion laser [15] followed closely obviously and closely joined together so far as our ideas and by the argon ion laser [16]. At Bell Telephone Laboratory, applications are concerned. scientists doped rare earth atoms into crystals and demon- Modern lightwave developments are helping us both strated a flashlamp-pumped Nd : YAG laser [17]. The technologically and scientifically. The discovery of the leading journal of the field, the IEEE Journal of origin of our universe, precise measurements of the dis- Quantum Electronics, listed each new laser and laser tance to the moon, and an enormous increase in the wavelength discovered.