3/7/2022 Jenny Applequist for HMNTL
A contribution to VCSEL laser technology, with a wide range of potential applications, was judged the best student presentation at the 2021 conference.
Written by Jenny Applequist for HMNTL
The International Conference on Compound Semiconductor Manufacturing Technology (CS MANTECH) has announced the winner of its Best Student Paper award from among the papers presented at the 2021 conference: “Standing Wave Engineering for Mode Control in Single-Mode Oxide-Confined Vertical-Cavity Surface-Emitting Lasers,” authored by Kevin Pikul, Patrick Su, Mark Kraman, Fu-Chen Hsiao, and John M. Dallesasse.
It was selected as the winner based on votes received in an attendee feedback form, along with paper ratings submitted through an online conference app.
The research of lead author Kevin Pikul, a Ph.D. student in ECE advised by John Dallesasse, is dedicated to maximizing the capability of vertical-cavity surface-emitting lasers (VCSELs) to operate in a single-fundamental-transverse mode, a regime advantageous for many applications in the realm of 3D sensing—such as Time-of-Flight (ToF) Light Detection and Ranging (LiDAR) in autonomous driving vehicles and facial recognition systems.
Pikul says that the winning paper’s innovation was in the use of a silicon coating on a VCSEL. “To my knowledge, the method of using a silicon anti-phase coating, just a single annulus-shaped layer atop the VCSEL, hasn’t been presented [before] in the literature,” he says. “I’ve seen different materials... but I haven’t seen silicon, which for several reasons provides significant advantages over those other materials due to its higher refractive index [and its] capability to be easily deposited in an electron-beam evaporation system.”
“The capability to spatially control the threshold gain in a VCSEL using a simple, easily controllable deposition process provides a scalable method of creating devices that maintain single-mode operation over a wider power range,” adds Dallesasse. “We try to focus on methods that can plausibly scale to high volume, as many of the emerging commercial applications for these devices demand that. We’re hopeful that this mode control method might help to provide the type of performance needed to enable these applications.”
Pikul started his higher education at a community college in part for its low cost, but also as a venue to help him explore options: he knew he wanted to be an engineer, but hadn’t decided what field to home in on. He later transferred to UIUC, where he completed a Bachelor’s in Engineering Physics in 2018 and a Master’s in Electrical Engineering in 2021.
After he finishes his Ph.D., Pikul plans to start a career in industry: “I want to make an impact... I want to go down that route and see what differences I can make.” He notes that the VCSEL market is “booming” and that “there are so many opportunities out there!” However, longer term, he envisions some kind of return to academia, largely because of appreciation for the professors he’s studied with. “I know what the influences I had were able to do for me,” he says. “I want to do the same thing, to give back.”
Dallesasse is a professor in Electrical & Computer Engineering and the Holonyak Micro & Nanotechnology Lab. Su and Kraman, like Pikul, are graduate students in Dallesasse’s group; Hsiao completed his Ph.D. with Dallesasse in 2020 and is now a postdoc at NC State University.