Bahl wins Dean’s Award for Excellence in Research
MechSE’s Gaurav Bahl is one of six assistant professors to be awarded the 2018 College of Engineering Dean’s Award for Excellence in Research.
This award honors assistant professors for their research accomplishments and published papers within the past year.
Bahl received a B.Eng degree from McMaster University in Ontario Canada in 2005, and then continued to Stanford University, where he received an M.S. and Ph.D. in Electrical Engineering in 2008 and 2010, respectively. He has been an assistant professor in MechSE since 2012. He is also an affiliate of the Electrical and Computer Engineering Department and the Micro and Nanotechnology Laboratory.
Bahl’s research focuses on systems that incorporate both optical and mechanical elements. Particularly, he is interested in mechanisms where light interacts with photonic microdevices such as radiation pressure, gradient force, electrostrictive pressure, and photothermal effects.
In a recent project, the Bahl research group collaborated with the National Institute of Standards and Technology and the University of Maryland to create a technique for suppressing the scattering of sound waves from disorder within a material. All materials have defects, and consequently, energy is lost in transmission. It was found that the appropriate color of laser light can suppress the scattering caused by the material imperfection.
A few years ago, the Bahl group found chirality could be induced for light using an opto-mechanical phenomenon in which light couples with propagating sound waves, making them transparent, and only allows light to move in one direction, creating an optical impedance. The group prepared a chiral optomechanical system comprised of a silica glass resonator and a laser field propagating in a clockwise direction. The laser wavelength, or color, was arranged to optically dampen only clockwise sound waves, and create an impedance mismatch between clockwise and counterclockwise directions of propagation. They found a large reduction of scattering loss for counter- clockwise sound waves as they could not scatter in the clockwise direction. With this, the disorder in the resonator was suppressed. Practical applications of this concept would improve mechanics- based inertial navigation sensors in use today.