Tutorials

Speaker Name and Affiliation:  Hong X. Tang, Department of Electrical Engineering, Yale University

In this tutorial, I will discuss the design, fabrication and measurement of extremely scaled optomechanical and electro-optomechanical resonators on an integrated circuit platform. A number of milestone devices, including devices with ultrasmall mass approaching femtogram, devices with ultrahigh sensitivity at attometer per-root-Hz level, and devices operating at ultrahigh speed beyond 10GHz will be described. Low phase noise electro-optomechanical oscillator operating in microwave x-band will be presented as a specific example to showcase the powerful combination of electromechanics and optomechanics a hybrid AlN cavity piezo-optomechanics platform.

Hong Tang is Professor of Electrical Engineering, Physics and Applied Physics at Yale University. His research utilizes integrated photonic circuits to study photon-photon, photon-mechanics and photon-spin interactions. He joined Yale faculty as assistant professor in 2006. At Yale his group specializes in nanofabrication and precision measurement, spanning the fields of spintronics, NEMS, nanophotonics and optomechanics. He is a recipient of the NSF CAREER Award and a Packard Fellow in Science and Engineering.

Speaker Name and Affiliation:  Dr. Gaurav Bahl, University of Illinois at Urbana-Champaign

Our team’s work has focused on two uniquely different versions of optomechanics –(1) using Brillouin scattering to couple traveling optical waves to traveling acoustic waves in ultra-high-Q resonators ^[1]; and (2) on developing the first microfluidic optomechanical device ^[2] capable of high-throughput chemical/biological/physical investigations on arbitrary flowing analytes.

In my talk I will discuss the underlying mechanisms of Brillouin Optomechanics and the applications that we have explored in parametric self-excitation, optical cooling of acoustic modes, induced transparency, and optical nonreciprocity^[3]. Tangentially, using our opto-mechano-fluidic devices, we also have demonstrated that we can extract acoustic properties of fluids (viscosity, density, speed of sound) and high-throughput perform bioanalyte detection, only by using light. The new informational degrees-of-freedom provided by such opto-acoustic measurements could lead to surprising new sensor applications in the near future.

References

[1] Bahl et al, Nat. Phys. vol.8 no. 3, p.203, 2012

[2] Bahl et al, Nat. Comms. 4:1994, 2013

[3] Kim et al, Nat. Phys. vol.11 p.275, 2015

Dr. Gaurav Bahl is an Assistant Professor of Mechanical Science and Engineering at the University of Illinois at Urbana-Champaign (UIUC), and an Affiliate Faculty in the Department of Electrical and Computer Engineering. Dr. Bahl received his PhD and MS degrees in EE from Stanford University in 2010 and 2008, and BEng degree in ECE from McMaster University in 2005. He has authored the first experimental papers on parametric excitation and optical cooling through Brillouin Optomechanics, and on Opto-Mechano-Fluidic oscillators. His work on Brillouin systems (cooling and microfluidics) has been featured as a “(top-30) significant development in optics” for two years in a row in the Optics in 2012 and Optics in 2013 special issues of the OSAs monthly Optics & Photonics News magazine. Additional commentary by editors and prominent researchers on the significance of his Brillouin optomechanics work has appeared in Nature Physics, Nature Photonics, and many technical news outlets. Dr. Bahl is also a recipient of the US Air Force Young Investigator Award in 2015.

Speaker Name and Affiliation:  Prof. Peter T. Rakich, Yale University

We begin with a general introduction to optical forces in guided wave systems. These include radiation pressure, produced at waveguide boundaries, and material-induced forces produced by photoelastic response.  Through a diversity of interactions, these forces mediate efficient coupling to high frequency acoustic phonons (0.1-40 GHz) in systems ranging from bulk crystals, to optical fibers, and nano-scale optomechanical waveguides. We survey the different types of Brillouin coupling, and the diverse dynamics that they can produce in guided-wave systems. We introduce the essential physics of Brillouin amplification and lasing, progressing to a discussion of saturation, line-narrowing, and spectral purification. Using this foundation, we highlight the powerful properties of Brillouin lasers that have enabled low noise oscillators and navigational sensors. In addition, we survey unique microwave-photonic signal processing schemes that are now possible with on-chip Brillouin interactions, and conclude by discussing future directions.

Speaker Name and Affiliation:  Dr. Eric Burt, Jet Propulsion Laboratory, California Institute of Technology

In the first part of this tutorial I will give an overview of how atomic clocks work in general and then describe in detail the underlying physics.  Crucial to building atomic clocks is being able to measure their performance, so I will also describe the various metrics used.  In the second part of the tutorial, I will give several key examples that represent the range of microwave atomic clock applications.  These will include, small chip-scale clocks, engineered space clocks, ultra-stable trapped ion clocks, and accurate laser-cooled fountain clocks.  By the end of the tutorial, attendees should be able to understand the strengths and weaknesses of the various clock technologies and to understand talks given at the conference on this topic.

Eric Burt was born in Berkeley, California.  He received a B.S. degree with honors in mathematics from the University of Michigan, Ann Arbor, Michigan in 1979, a M.S. degree in physics from the University of Washington, Seattle, Washington in 1990 and a Ph.D. in physics from the University of Washington in 1995.  His Ph.D. thesis, supervised by Prof. Warren Nagourney, was in the field of experimental atomic physics on the trapping and laser-cooling single indium ions.   From 1995 to 1997 he was a postdoctoral fellow at the University of Colorado, in Boulder, Colorado working with Carl Wieman and Eric Cornell on experiments with Bose-Einstein condensates including the first experiment to demonstrate a dual-species condensate and the first experiment to demonstrate higher-order (laser-like) coherence in condensate atoms.  From 1997 to 2001 he worked at the U.S. Naval Observatory in Washington, D.C. developing a laser-cooled cesium fountain atomic clock.  From 2001 to the present he has worked at the Jet Propulsion Laboratory, California Institute of Technology as a Senior Member of Technical Staff.  His work at JPL has included development of both ion and laser-cooled neutral atomic clocks and using atomic clocks to place limits on fundamental constant variation.  Dr. Burt is a member of the American Physical Society, and the IEEE.  He is on the technical program committee for the IEEE Frequency Control Symposium and has served as the chair of that committee as well as vice-chair for group 3 (microwave atomic clocks).  He has also served on the steering committee for the APS Topical Group on Precision Measurement and Fundamental Constants.

Speaker Name and Affiliation:  Dr. Patrizia Tavella, Italian Metrology Institute, INRIM, Torino

Through the use of ultra precise atomic frequency standards, we can form time scales, such as the international time standard Universal Coordinated Time (UTC), capable of dating events with nanosecond accuracy. 

Similarly, Global Navigation Satellite Systems (GNSS), provide location all over the world with sub-meter accuracy. 

In timekeeping, as well as in navigation systems, the questions may be similar, but the answers are frequently dissimilar, due to different goals, requirements, technology availability and constraints.

In both cases precision clocks, measuring systems, and a reference time scale are required; in both cases we need to estimate how often the clocks are to be resynchronized and what is the acceptable time error that a clock may accumulate without compromising system performance.

We require a mathematical model to predict clock behavior in order to maintain agreement with another reference clock or to ensure updated navigation messages. We need to understand the “normal” behavior of a clock to be able to quickly identify anomalies which can lead to incorrect estimates.

The lecture presents the needs of precise Timing and Navigation, explaining the current international timekeeping architectures and the timing systems of the current GNSS, giving insight to the most demanding topics that still challenge Time Metrology.

Patrizia Tavella, degree in Physics and Ph.D. in Metrology, she is now senior scientist with the Italian Metrology Institute, INRIM, Torino, Italy. Her main interests are mathematical and statistical models mostly applied to atomic time scale algorithms. She chaired the working groups on “International Atomic Time” and “Algorithms” of the Consultative Committee of Time and Frequency. She is deeply involved in the development of the European Navigation System Galileo.  She is currently IEEE UFFC Distinguished Lecturer.

Speaker Name and Affiliation:  Dr. Chris Oates, NIST-Boulder

Chris Oates is the leader of the Optical Frequency Measurements Group in the Time and Frequency Division of the National Institute of Standards and Technology in Boulder, CO.  Dr. Oates joined NIST in 1995 after receiving his Ph.D. from the University of Colorado in the group of Nobel Laureate John Hall. Previously he had earned a B.S. in Physics from Stanford University in 1984 after which he spent two years with Peace Corps teaching physics on a small Caribbean island. Dr. Oates has authored and co-authored more than 100 scientific papers in the field of high-resolution spectroscopy/optical clocks and has received two Department of Commerce Gold Medals for this research. He also serves on the Working Group for Frequency Standards at the International Bureau of Weights and Measures (BIPM).

Speaker Name and Affiliation:  Dr. Svenja Knappe, NIST-Boulder

The tutorial will cover the basic principles of the underlying spectroscopy of these sensors, as well as specific operating principles and designs. It will cover state-of the art commercially available sensors as well as recent advances in basic research.

Speaker Name and Affiliation:  Prof. Ashwin A. Seshia, University of Cambridge

Ashwin A. Seshia received his BTech in Engineering Physics in 1996 from IIT Bombay, MS and PhD degrees in Electrical Engineering and Computer Sciences from the University of California, Berkeley in 1999 and 2002 respectively, and the MA from the University of Cambridge in 2008. During his time at the University of California, Berkeley, he was affiliated with the Berkeley Sensor & Actuator Center. He joined the faculty of the Engineering Department at the University of Cambridge in October 2002 where he is presently a Reader in Microsystems Technology and a Fellow of Queens' College. His research interests are in the domain of microengineered dynamical systems with applications to sensors and sensor systems. Dr Seshia serves on the editorial boards of the IEEE Journal of MicroElectroMechanical Systems, the IEEE Transactions on Nanotechnology and the IEEE Transactions on Ultrasonics, Ferroelectrics and Frequency Control.

Speaker Name and Affiliation:  Prof. David Horsley, University of California Davis

David A. Horsley received his PhD in Mechanical Engineering from the University of California, Berkeley, in 1998. From 1998 to 2003, he held research and development positions at Dicon Fiberoptics and Hewlett Packard Laboratories and helped to co-found Onix Microsystems, a manufacturer of fiber-optic switching components. In 2003, he joined the Department of Mechanical Engineering, University of California Davis, Davis, CA. Since 2005, he has been a Co-Director of the Berkeley Sensor and Actuator Center (BSAC), the National Science Foundation’s Industrial/University Collaborative Research Center (I/UCRC) focused on MEMS research. Professor Horsley is the Co-Founder of Picosense Inc, a developer of low-noise magnetoresistive sensors, and the Co-Founder and CTO of Chirp Microsystems Inc., a manufacturer of ultrasonic sensors using MEMS technology. He is the General Co-Chair of IEEE Sensors 2016, to be held in November 2016 in Orlando, FL. He is a recipient of the National Science Foundation’s CAREER Award and the Outstanding Junior Faculty Award at UC Davis. He has authored or co-authored over 150 scientific papers and holds over 15 patents.

Speaker Name and Affiliation:  Vikrant Gokhale, NIST

Vikrant Gokhale (S’10-M’14) is currently apostdoctoral researcher in the Nanoscale Metrology Group at the National Institute of Standards and Technology (NIST) in Gaithersburg, MD. He received his B. Tech in Electronics and Instrumentation Engineering from the Vellore Institute of Technology, India in 2007. From 2007 to 2008, he was an engineer at Honeywell Sensing and Controls where he worked on smart MEMS pressure sensors. He received his M.S. (2010) and Ph.D. (2014) degrees in Electrical Engineering and Computer Science at the University of Michigan. Vikrant’s dissertation research includes the development of GaN and AlN MEMS resonators as low-noise, sensitive uncooled infrared detectors and detector arrays with configurable absorber coatings. At NIST, Vikrant’s projects include the use of optical characterization techniques to better understand the femtometer scale dynamics and loss mechanisms of high-frequency MEMS resonators. His research interests include GaN MEMS device and sensor design, dynamics of high frequency resonators, and phonon-electron interactions in piezoelectric semiconductors.