Lasers, optics, robots all part of the job


Dr. Darby Hewitt plays with toys for a living.

As assistant professor of engineering and physics, he spends his time researching lasers and teaching students how to build robots. And it’s all part of his job.

After earning a degree in physics from ACU in 2008, Hewitt went on to earn his master’s and Ph.D. in electrical and computer engineering at the University of Illinois, one of the top engineering graduate programs in the nation.

His passion for teaching led him back to ACU.

Hewitt holds a patent, is involved in laser research and is the assessment coordinator for the accreditation of ACU’s engineering program.

He also started a robotics team with his engineering students. The students have taken their line­following robots to local schools and most recently participated in ACU’s first Maker Fest sponsored by the Maker Lab.

Robotics team members (from left) are Brandon Canterbury, Tanner Marlar, James Mallon, Kanden Slaton and Sonia Cyuzuzo. Dr. Darby Hewitt is in front.

Sparking the light

As a child, Hewitt was fascinated by electronics and circuits.

“Robots were cool to me,” he said.

He hadn’t intended to attend ACU until he started dating a girl who planned to. He decided to follow her – they eventually got married – and study physics at ACU.

He was glad he did. ACU’s physics program, known internationally for its undergraduate research opportunities, prepared him for acceptance into an engineering graduate program ranked in the Top 10 by U.S. News & World Report.

While in graduate school, Hewitt became interested in optics and lasers through an electrical engineering class.

“The focus was multidisciplinary,” he said. “You had to know a little bit about atomic physics, you had to know about optics, and you had to know about quantum mechanics.”

After that class, Hewitt decided to pursue his graduate studies in engineering with a focus on lasers and optics.

Although Hewitt focuses his research on optics, his true passion lies in teaching.

Models of inspiration

Hewitt’s interest in teaching was sparked by his mother, a math professor at a community college in Waco. During his years at ACU, he became more interested in teaching after he began tutoring other students in calculus and math.

He also was inspired by his graduate advisor, Gary Eden, a member of the National Academy of Engineering. Eden was a Christian, something Hewitt said he had not expected at a secular school. Hewitt said Eden was a kind and compassionate teacher, showing him academic skills as well as personal skills. Eden taught him to have confidence about his research and present it with certainty.

Now Hewitt applies what he learned from Eden and his ACU professors as he teaches optics, electric circuits and digital logic.

Laser optics research

Hewitt’s graduate research focus was on laser science. For his master’s thesis, Hewitt used a pulsed ultraviolet laser like an “energy hammer” to excite crystalline materials. He studied the laser-induced fluorescence of those materials to determine the energy structure of impurities in their composition.

Hewitt wrote his graduate dissertation on the study of atom-atom interactions within mixtures of alkali vapor and noble gases. These gas mixtures serve as the gain media for a relatively new category of lasers which could potentially be scaled to high-power output with a small footprint and relatively high efficiency. These laser systems could be useful for laser machining or for defense applications.

During the summers of 2014 and 2015, Hewitt and his students worked to computer-control a monochromator. Although the machine was old, built in the 1960s, they were able to modernize it by equipping it with a motor controller and automation interface. The machine works like a prism but is much more efficient, diffracting white light into a spectrum that can be analyzed.

“It’s not anything new but the great thing about it was that it was super cheap,” Hewitt said. “We revitalized it and increased its usability.”

The students had the opportunity to apply programming skills and knowledge about light, diffraction, and engineering mechanics from class to a real machine. Hewitt said the machine has several applications and can be used for both laser and materials research.

Hewitt has received internal grants for his laser science and optics research. He collaborated with chemistry professor Dr. Greg Powell to use lasers to analyze new compounds that Powell had discovered.

The complexity of God

When it comes to his faith, Hewitt said the study of physics helps him gain a fuller appreciation for the complexity of God. The more he researches, the more awed he is by the processes God created.

“You gain an appreciation for how unknowable and big God is,” Hewitt said. “The Grand Engineer of the Universe is powerful.”

Hewitt said he hopes to incorporate laser science and engineering with embedded systems in his research. He also wants to inspire more students to become involved in research experiences that will be significant to their future careers.