CREOL Advances Light as the Gateway to Technological Advances

Abstract

THE UNIVERSITY OF CENTRAL FLORIDA'S (UCF) CENTER FOR RESEARCH IN Optics and Lasers (CREOL) program has come a long way since its first incarnation in a double-wide trailer in 1987. The center became a college in its own right in 2004, still under the auspices of UCF, and it has attracted some of the best and brightest minds in optics and photonics.

In 2023, UCF was named one of the world's top 25 universities for optics, recognizing the CREOL program specifically for excellence in research. The CREOL program has uncovered many previously unknown properties of the materials used in optical and display devices. Its researchers have gone on to invent and implement many practical applications within the visual display industry, from head-up displays in cars to ultrahigh-resolution screens used in virtual reality (VR) headsets, to more traditional consumer and commercial LCD panels and projection systems.

CREOL offers an interdisciplinary undergraduate program as well as graduate programs that lead to MS or PhD degrees in optics and photonics. Optics usually refers to light propagation in a medium, such as air, water, lenses, prisms, or mirrors. As a result of this propagation, the light could be scattered, absorbed, focused, refracted, or reflected. Some familiar natural optical phenomena include rainbows and the color of the sky as light reflects and refracts through our atmosphere. In scientific terms, a common research area in optics is the “nonlinear effect,” where the intensity of transmitted light does not correspond precisely to measured light in a system.

Photonics, also known as optoelectronics, usually refers to light generation, propagation, and detection. Some common examples of light generation include light bulbs, LED elements, and lasers. Different forms of generated light could propagate in vacuum for space communications, in fibers for long-haul data communications, in an assembly of lenses and mirrors for a projection system, or in a light guide plate for display applications. The science and study of photonics normally involves equipment such as detectors, power meters, and image sensors. Although optics and photonics both deal with light and its properties, the areas of focus can be quite different, depending on whether the component is passive or active.

CREOL currently has approximately 35 faculty members, 30 postdocs, 100 graduate students, and 100 undergraduate students. Its research can be roughly grouped into five clusters: lasers; nonlinear and quantum optics; fiber optics; optoelectronics and integrated photonics; and imaging, sensing, and displays. All students are encouraged to participate in research. Some undergraduate students stay to continue their advanced degree at CREOL (Fig. 1).

As with many institutions, funding is an important pillar of CREOL's continued success. The college's annual operating budget is ∼$20–$25 million, with funding received from a diverse blend of sources, including the National Science Foundation, National Institutes of Health, Defense Advanced Research Projects Agency, Department of Defense, government labs, private industry, the state of Florida, and additional private donors. CREOL continues to thrive and actively hire new faculty for its growing programs.

The college is best known for its high-power lasers, ultrashort (attosecond) pulse lasers, and studies on nonlinear optics. Several faculty members have received prestigious society awards, such as the Optica R. W. Wood Prize, American Physical Society Arthur L. Schawlow Prize in Laser Science, and International Society for Optics and Photonics (SPIE) Gold Medal. CREOL's Professor Shin-Tson Wu, Fellow of SID, recently was ranked first by the ScholarGPS organization in research for liquid crystal technology. This includes not only academic researchers but those in private industry and government.

Most of CREOL's graduate students are offered internships, either at private companies or government laboratories, before they graduate. After graduation, approximately 90 percent of the program's PhD students join industry and 10 percent join academia. Corporate researchers have been known to visit CREOL to participate in sponsored research (Fig. 2).

Most PhD students publish several papers before graduation. In Wu's group, “at least two PhD students published 40 peer-reviewed journal papers before graduation. Their publications also received outstanding citations. Presenting papers in a conference, such as the Society for Information Display's Display Week, is an important learning and growing experience (see sidebar). By attending conferences, students may be inspired with new ideas. Some of my students met their future employers at a conference,” he said.

Career paths vary for students in each study cluster. For those focusing on display science and technology, companies such as Apple, Meta, Applied Materials, Microsoft, Google, and Magic Leap have proven to be attractive workplaces. The research and development centers of display makers, such as Samsung, LG Display, BOE, TCL, and Sony, are mostly based in Asia but offer branch offices in the United States, making them prospective employers.

Some graduates and faculty have chosen to blaze their own trails with spin-off companies and start-ups. CREOL Research Professor Leon Glebov started a company called OptiGrate, which specializes in volume Bragg gratings (VBGs)—optical devices that have a one-dimensional periodic refractive index modulation within a transparent material. A typical practical application of VBGs is in stabilizing the wavelength of laser diodes, such as those used in commercial and consumer projectors. In 2017, IPG Photonics Corporation acquired OptiGrate. Later, Glebov's family donated seed funding, enhanced with SPIE's generous matching fund, to establish scholarships to support CREOL students.

CREOL alumnus Jason Eichenholz is the co-founder and chief technology officer of Luminar Technologies, a sensing technology company that offers a core platform to enable safe, fully autonomous vehicles. He is responsible for the research and development of new products and bringing the company's technology to market.

Many CREOL graduates and faculty members have been granted patents within the display industry. Glebov received more than 15 patents in Russia before immigrating to the United States, where he was granted an additional patent while at CREOL. Wu holds 96 US patents with a dozen patents pending, some of which have been used in current display products. Perhaps the most notable of these is the mixed-mode twisted nematic (MTN) reflective LCD. MTN has enabled two new product categories: direct-view sunlight readable LCD displays and pico-projectors for augmented reality (AR) glasses. The former has been commercialized by companies such as AUO and BOE, the latter by Himax and others for the Microsoft HoloLens, Magic Leap 2, and Lumus AR glasses.

The CREOL program continues to attract new interest with approximately 25 PhD candidates, 30 master's candidates, and 60 undergraduate students joining the program every year (Fig. 3). When asked about which research areas hold the most promise for advancing the display industry, Wu highlighted artificial intelligence, quantum computing, digital twins, spatial computing, and the Metaverse as promising emerging fields related to optics and photonics. (A digital twin is a virtual model designed to accurately reflect a physical object. Once the model is validated, it can be applied back to improve the functionalities of the original physical object.)

“Lately, my group has made a lot of progress in AR displays, including ultracompact light engines such as microLEDs, micro-OLEDs, and liquid crystal-on-silicon displays with high-efficiency waveguides and low power consumption. Several industrial giants are also investing in manufacturing lightweight AR glasses. We hope to see several low-cost, lightweight, and stylish AR glasses being introduced over the next two to three years.”

When asked about his proudest achievement to date, Wu said, “I have nothing to be proud of by myself. My achievements represent the teamwork accumulated from my group members, including my present and former students and visiting scholars. Based on their scientific discoveries and technical achievements, jointly we made a small step toward a tangible impact on the quality of life, economic development, and welfare of society.”