Paul Leisher

Paul Leisher
Paul Leisher
  • MS 2003 EE, PhD 2005
  • Thesis title: “Proton Implanted Photonic Crystal and Holey Vertical Cavity Surface Emitting Lasers”

When he was an electrical engineering graduate student at Illinois, Paul Leisher, enjoyed teaching undergraduates about lasers and optics as a teaching assistant. After a successful stint in industry, Leisher has returned to the classroom as an associate professor of physics & optical engineering at Rose-Hulman Institute of Technology in Indiana, where he also supervises undergraduates’ research projects.

Leisher, who joined the Rose-Hulman faculty in 2011, has taught courses in geometric optics, lens design, semiconductor physics, semiconductor devices, a laser physics lab, as well as an introductory (100-level) course in optics and technology. According to Leisher, even when he was an Illinois graduate student, he knew he ultimately wanted to be a professor.

Although Rose-Hulman’s primary focus is undergraduate education, Leisher has established a research lab, where he can supervise students’ projects on the design and characterization of high-power semiconductor lasers.

After earning his doctorate in 2007, Leisher worked at nLight Corp for several years, starting as a device engineer and working his way up to be manager of advanced technology. He helped develop high-power semiconductor lasers. He also managed the writing of grant proposals for these lasers and oversaw the funding for their development.

Leisher recalls his mentors at nLight were "fantastic and taught [him] a lot," which was very beneficial as he was the company's first entry-level hire straight out of school. According to Leisher, when someone asked him for help, he prioritized this above other things and he credits this for helping his career in many ways.

As a professor, Leisher has stayed active in the industry through consulting jobs with seven companies over the last three years—from small (approximately 20-person staffs) to Fortune 500 companies both in the United States and abroad. In his consulting role, he has done technical consulting for high-power semiconductor diode laser development and manufacturing including the design, fabrication, characterization, data analysis and reliability. Within his community at Rose-Hulman, staff are encouraged to stay active in the industry as well to provide a link for students through professors to the industry.

Taking a look back to his graduate student days in ECE Professor Kent Choquette's group at Illinois, Leisher remembers late nights and long hours in the clean rooms conducting research on vertical-cavity surface-emitting lasers while the rest of the building was a construction zone, undergoing a two-year expansion to add lab, research, classroom, and meeting space.

Another thing Leisher remembers was the competitive atmosphere that surrounded research conducted in the laboratory. He wants current and future students to realize it is mutually beneficial to approach research in a cooperative manner. He advises students to help others when asked because there will come a time when you need help in return.

"In the long term this results in many positive things including a better understanding of others and your own research," Leisher said. "I want my students to know that everyone is in the same boat together."


  1. At nLight he developed a technique for stabilizing the wavelength of a semiconductor that allows spectral brightness to be improved without penalizing the efficiency of the laser.
  2. The joy he gets each day when students enrolled in his classes graduate and go off to get jobs. "It is really satisfying when a former student contacts me and says 'thanks.'" Leisher said.
  3. The birth of his son in the summer of 2014