Bahl Research Group
Exploring chiral physics in ultra-high Q whispering gallery resonators.
S. Kim, X. Xu, J.M. Taylor, G. Bahl, "Dynamically induced robust phonon transport and chiral cooling in an optomechanical system", Nature Communications 8, 205, doi:10.1038/s41467-017-00247-7, 2017. [Nature link]
Photograph of fluid meniscus in an ultrahigh-Q opto-mechano-fluidic resonator (OMFR).
K. Han, J. Kim, G. Bahl, "High-Throughput Sensing of Freely Flowing Particles with OptoMechanoFluidics", Optica, vol.3, no.6, pp. 585-591, 2016. [Optica link]
Artist visualization of Raman Cooling of a silicon photonic crystal.
Y. Chen, G. Bahl, "Raman Cooling of Solids through Photonic Density of States Engineering," Optica, 2(10), p.893-899, 2015. [Optica link]
Visualization of slow, fast, and stopped light in Brillouin Scattering Induced Transparency.
J. Kim, M. Kuzyk, K. Han, H. Wang, G. Bahl, "Non-reciprocal Brillouin scattering induced transparency," Nature Physics, 11, pp. 275-280, doi:10.1038/nphys3236, 2015. [Nature link]
Laser draw-casting fabrication of ultralong metal nanowires within OMFRs.
K. Zhang, K. Han, S. Shi, G. Bahl, S. Tawfick, "Highly Stretchable Conductors Made by Laser Draw-Casting of Ultralong Metal Nanowires," Advanced Electronic Materials, doi:10.1002/aelm/201600003, 2016 [Wiley link]

Gaurav Bahl [CV]
4413 Mechanical Engineering Laboratory,
105 S. Matthews
Urbana, IL 61801

Tel: (217) 300-2194

Research Overview

The Bahl Research Group performs experimental research at the interface between optical and mechanical systems. Of particular interest are the mechanisms by which light interacts mechanically with photonic microdevices (i.e. via radiation pressure, gradient force, electrostrictive pressure, and photothermal effects), and how mechanical devices can affect and manipulate light.

See Research for more details.


We are always on the lookout for graduate and undergraduate researchers with background in the following topics -- electromagnetics, photonics, microfabrication, material physics, nonlinear optics, MEMS and NEMS, and circuit design. Experimental experience is strongly preferred. Interested students must already be admitted to UIUC and should contact Prof. Bahl with a complete CV highlighting relevant experience.

Latest News

7 Aug 2017
Seunghwi's paper on chiral optomechanical cooling and disorder suppression appears in Nature Communications. The work is also featured by the UIUC College of Engineering.

24 July 2017
Congratulations to Dr. Inbar Grinberg on winning postdoctoral fellowships from both the Zuckerman STEM Leadership Program and the Israel council for higher education.

12 May 2017
Congratulations to Kewen on winning a 2017 Chinese Government Award for outstanding students studying abroad.

8 May 2017
Congratulations to JunHwan and Seunghwi on getting their paper on achieving complete optical isolation published in Scientific Reports! The work was also featured by the College of Engineering.

24 Apr 2017
The College of Engineering recognizes numerous young faculty awards netted by our faculty.

16 Feb 2017
Congratulations to (nearly Dr.) Kewen Han on passing his PhD defense!

7 Feb 2017
Gaurav has won a ONR Director for Research Early Career grant ($1M) to pursue experimental research on reconfigurable microwave and acoustic nonreciprocal systems.

13 Jan 2017
Seunghwi's paper on dual optical densities of states on Brillouin cooling appears in Optics Express. The work demonstrates operation close to strong coupling and saturation of Brillouin cooling.

21 Dec 2016
Jeewon's paper in APL Photonics presents the fastest fly-by optomechanical particle sensor to date, capable of speeds exceeding 30,000 particles/second.

29 Nov 2016
Yinchung and Seunghwi reveal the regimes of operation of Brillouin cooling in linear waveguides in the New Journal of Physics.

17 Sept 2016
The work of our EFRI teammate (Prof. Steven Cummer, Duke) is featured as part of the National Science Foundation #waveweek series.

15 Aug 2016
Our team has won a major research grant to explore New Light and Acoustic Wave Propagation (NewLAW), funded through the NSF Emerging Frontiers in Research and Innovation (EFRI) program. This 4-year research project will be conducted in close collaboration with our co-PIs Prof. Taylor Hughes (UIUC Physics), Prof. Steve Cummer (Duke ECE), and Prof. Hailin Wang (Oregon Physics). Article from Engineering@Illinois

22 June 2016
Our opto-mechano-fluidics research is featured on the cover of the June 2016 edition of Optica.

1 June 2016
Our paper on High-Throughput Sensing of Freely Flowing Particles with OptoMechanoFluidics is published in Optica!

21 May 2016
Kitt Peterson's fantastic outreach efforts with middle-school children are featured in I-STEM and MechSE Today. Kitt taught students how to design and 3D print their own keychains!

29 March 2016
Congratulations to Christopher Peterson for winning a National Science Foundation Graduate Research Fellowship for 2016.
Our group continues to maintain its 100% success rate on this program with three fellowship recipients till date!

8 March 2016
Our group has won a DURIP award from AFOSR to build a telecom wavelength Raman spectrometer!

4 March 2016
Congratulations to Kewen for winning a 2016 Yee Fellowship from the College of Engineering!

19 Februrary 2016
Congratulations to Kewen for being honored by MechSE as a Distinguished Graduate Student for 2015!

29 January 2016
Congratulations to Seunghwi and Yin-Chung on passing their qualifying exams!

23 September 2015
Multiple updates! -- Nathan and Seunghwi's paper on Giant Gain Enhancement in Surface-Confined Resonant Stimulated Brillouin Scattering is accepted for publication in Laser & Photonics Reviews. Gaurav's chapter on Microfluidic Optomechanics for the 2015 edition of the Encyclopedia of Nanotechnology is also accepted. Gaurav celebrates 5 years since receiving his PhD.

15 September 2015
Our paper on Raman Cooling of Solids through Photonic Density of States Engineering is accepted for publication in Optica.

15 April 2015
Congratulations to Jafir for winning an undergraduate research grant from the MechSE Society of Engineering Mechanics.

31 March 2015
Benjamin Sohn was awarded a National Science Foundation Graduate Research Fellowship. Congratulations on this fantastic achievement!

26 January 2015
Non-Reciprocal Brillouin Scattering Induced Transparency appears in Nature Physics.
Congratulations to the team and to our collaborators from Oregon.
Associated news story here.

20 January 2015
Gaurav wins the AFOSR Young Investigator Award (YIP) for proposed work on Chip-Scale Linear Non-Reciprocal Optomechanical Systems. Several major victories for Illinois Engineering.

2 December 2014
Benjamin's outreach efforts with students at the Dr. Howard Elementary School in Champaign are featured on I-STEM.

15 October 2014
Gaurav Bahl, Benjamin Sohn, Shengtai Shi, and Joseph Muskin spent the week at University of Illinois Laboratory High School working with Sharlene Denos and her class on resonant optomechanical sensors.

26 August 2014
It's been a good summer with papers in Journal of Visualized Experiments, Applied Physics Letters, European Physical Journal, and Scientific Reports! Good work team!

1 April 2014
Congratulations to Nathan for winning the NSF Graduate Research Fellowship!

14 Jan 2014
Congratulations to Kewen and JunHwan for their Optics Express paper on multimode aerostatically tunable optomechanical oscillators.

2 December 2013
Nathan's educational activities with 4th graders at Stratton Elementary school are featured in the MechSE weekly news and on the I-STEM website.

26 November 2013
Optics in 2013: "Bridging two worlds: Microfluidic optomechanics" appears in OPN Magazine December 2013 issue (pg. 39). This issue of the monthly magazine of The Optical Society highlights the most exciting optics research to emerge in the preceding 12 months.

11 November 2013
"Cavity optomechanics on a microfluidic resonator with water and viscous liquids" appears in Light Science & Applications .

15 October 2013
Kyu Hyun Kim's paper on Microfluidic Optomechanics is a winner of the Emil Wolf Outstanding Student Paper Competition at Frontiers in Optics 2013.

7 October 2013
Optics in 2013! Each year, the December issue of Optics & Photonics News - the monthly magazine of The Optical Society - highlights the most exciting optics research to emerge in the preceding 12 months. Our submission on Microfluidic Optomechanics has been selected this year!

8 July 2013
Kewen's first conference paper on multi-mode optomechanical pressure sensing is accepted to Frontiers in Optics 2013. Congratulations!

7 Jun 2013
"Brillouin cavity optomechanics with microfluidic devices" appears in Nature Communications. The work is featured on,, and UIUC College of Engineering.

29 Apr 2013
Our research on Brillouin cooling is highlighted in Nature Photonics, Vol. 7, 348-349 (2013) in article titled View from... 2013 Photonics West: Solid cooling.

1 Dec 2012
Our work on Brillouin cooling is featured in the OSA Optics and Photonics News "Optics in 2012" issue which highlights the most exciting optics research to have emerged in the past 12 months.

7 Aug 2012
New course offered: ME498-PM4 Photonic MEMS. Read more.

19 Apr 2012
Gaurav will start as MechSE faculty at UIUC in Fall 2012!

22 Jan 2012
"Observation of spontaneous Brillouin cooling" appears in Nature Physics.

22 Jan 2012
Our work on Brillouin cooling is featured in Nature Physics News & Views!

List of Publications

Click here for Publications page.