Eli Yablonovitch (born 15 December 1946) is an American physicist and engineer who, along with Sajeev John, founded the field of photonic crystals in 1987.[1] He and his team were the first to create a 3-dimensional structure that exhibited a full photonic bandgap, which has been named Yablonovite. In addition to pioneering photonic crystals, he was the first to recognize that a strained quantum-well laser has a significantly reduced threshold current compared to its unstrained counterpart. This is now employed in the majority of semiconductor lasers fabricated throughout the world. His seminal paper[2] reporting inhibited spontaneous emission in photonic crystals is among the most highly cited papers in physics and engineering.
After receiving his Ph.D., Yablonovitch worked at Bell Laboratories. He then became a professor of applied physics at Harvard in 1974. In 1979, he joined Exxon research center to work on photovoltaic research for solar energy.[4] While working at Exxon, Yablonovitch derived the 4 (n squared) factor as the theoretical limit for light trapping in photovoltaics. This is now used worldwide in almost all solar panels.[3]
Yablonovitch joined Bell Communications Research in 1984, and became its director of solid-state physics research in 1991. During his time at Bell Communications, Yablonovitch did his pioneering work on photonic crystals.[1][4]
Yablonovitch has co-founded multiple companies related to his research interests. In 2000, he co-founded Ethertronics Inc. Ethertronics is a cell phone antenna manufacturer that has, to date, shipped over 1.7 billion antennas.[4]
In 2001, Yablonovitch co-founded Luxtera Inc., a semiconductor company that makes electro‑optical systems using silicon photonics, manufactured with CMOS processes. Luxtera is the first company to market foundry-based silicon photonics.[4][5]
Yablonovitch co-founded Luminescent Inc. in 2002. Luminescent provided sophisticated mathematical optimization for use in photolithography masks. Luminescent was acquired by Synopsys in 2012.[4]
In 2008, Yablonovitch founded Alta Devices Inc. Alta Devices produces thin-film gallium arsenide photovoltaic cells for solar energy. Alta Devices currently holds the efficiency world record for single junction solar cells at 29.1% and dual junction solar cells at 31.6%, both at 1 sun illumination.[3][6]