Columbia Engineering researchers have built a Kerr frequency comb generator that, for the first time, integrates the laser together with the microresonator, significantly shrinking the system’s size and power requirements. They designed the laser so that half of the laser cavity is based on a semiconductor waveguide section with high optical gain, while the other half is based on waveguides, made of silicon nitride, a very low-loss material. Their results showed that they no longer need to connect separate devices in the lab using fiber—they can now integrate it all on photonic chips that are compact and energy efficient.
Columbia Engineering researchers have created the first flat lens capable of correctly focusing a large range of colors of any polarization to the same focal spot without the need for any additional elements. Only a micron thick, their revolutionary "flat" lens is much thinner than a sheet of paper and offers performance comparable to top-of-the-line compound lens systems. The findings of the team, led by Nanfang Yu, associate professor of applied physics, are outlined in a new study, published by Light: Science & Applications.
Prof. Yuan Yang, Prof. Nanfang Yu, and Jyotirmoy Mandal (a doctoral student in Yang's group) invented a high-performance exterior PDRC polymer coating with nano-to-microscale air voids that acts as a spontaneous air cooler and can be fabricated, dyed, and applied like paint on rooftops, buildings, water tanks, vehicles, even spacecraft—anything that can be painted. They used a solution-based phase-inversion technique that gives the polymer a porous foam-like structure. The study is published online in Science.
Siu-Wai Chan, Professor of Materials Science and Engineering, was elected a 2018 APS Fellow "for observing and understanding the grain boundary dislocation motion in materials, providing a seminal impact on superconducting thin film boundary devices, and inventing a novel ecological synthesis technique of nano-crystals oxides for catalysis applications."
Adam Sobel, Professor of Applied Physics and Applied Mathematics and of Earth and Environmental Sciences, was featured on NBC's Today show in an interview with Harry Smith on the "Science Behind the Storm: Role of Climate Change in Fueling Florence."