Colloquium 10/13: A Sound Way to Measure Nanostructures: Ultrafast Optics and Picosecond Ultrasonics

Title: A Sound Way to Measure Nanostructures: Ultrafast Optics and Picosecond Ultrasonics

Speaker: Brian Daly, Vassar College

Abstract: We can take it for granted that progress in nanoscale science and technology in the coming decades will depend heavily on imaging and sensing methods with nanometer resolution. A number of established techniques can provide us with this resolution (e.g. electron microscopy, atomic force microscopy) but these are restricted to objects on or very near the surface of a sample. A wide range of nanostructures are currently under development across the spectrum of the sciences, and in many cases these structures come in the form of multi-layered stacks. As such, a method for the study of buried nanostructures and films is required.

One solution to this problem is to use ultrasound, which has been successful in medical and industrial fields for imaging with optimum resolution in the range of 10’s to 100’s of micrometers. In order to obtain nanometer scale resolution, we must use waves that have a much shorter wavelength (higher frequency) than traditional ultrasound. To do this, we use one of the most versatile tools of the quantum mechanical age, the ultrafast laser. An ultrafast laser produces pulses of light that are shorter than 1 picosecond, and when these pulses are absorbed by a solid layer, they generate extremely high frequency sound waves: what we like to call “Picosecond Ultrasonics.”

In this presentation I will give an overview of the way in which we use light to generate and detect high-frequency ultrasound in solid samples. I will also describe a companion technique for measuring thermal properties of nanoscale films known as Time-Domain Thermoreflectance

As always, lunch will be provided at 12:20 in Room N304, and all are welcome. The full schedule for the Fall term Physics and Astronomy Colloquium Series is here.

Summer Student Poster Session to Kick Off Fall 2011 Colloquium

The Nth Annual Summer Student Poster Session will be held this Thursday, September 15. Students who did summer research projects either on campus or at other institutions will give posters on their work in the halls of the Department of Physics and Astronomy, beginning at 12:20 pm. As always, lunch will be provided at 12:20 in Room N304, and all are welcome to come hear about the exciting activities of our students.

The poster session is also the traditional kick-off for the Fall term Physics and Astronomy Colloquium Series, the full schedule for which is here.

Graduation 2011

Physics students, faculty, and alumni at graduation 2011

Congratulations to the graduates of the class of 2011!

Left to right: Richie Bonventre ’08, Mike Mastroianni ’07, Prof. Wilkin, Tom Perry ’09, Katie O’Brien, Michael Varughese, Peter Bonventre, Prof. Orzel, Prof. LaBrake, Chad Harrington, Danny Barringer, Pam Urresta, Prof. Surman, Prof. Vineyard, Colin Gleason, Prof. Marr.

Union Wins Outstanding Chapter Award from SPS

The Union College chapter of the Society of Physics Students was recognized as an outstanding chapter for 2010, one of just 50 chapters nationwide (out of more than 700 nationwide) given this award. Union was cited for “Extensive outreach, community service, and social activities.” This is the second year in a row that Union has earned this distinction.

Congratulations to all the SPS students whose hard work has made this possible.

Prof. Orzel Speaks at AAAS Meeting

Associate Professor Chad Orzel gave a presentation at the 2011 annual meeting of the American Association for the Advancement of Science in Washington, DC, as part of a symposium titled “Science Without Borders: Learning from TIMSS Advanced 2008,” about the Trends in International Math and Science Survey, an international test of math and physics given to students in nine countries. Chad’s talk, “What Physics Knowledge Is Assessed in TIMSS Advanced 2008?” evaluated the content of the physics test by comparing them to college and high school curricula and tests developed through physics education research. Other speakers in the symposium included representatives from the international study center that administers TIMSS, and from the national test centers in Norway and Slovenia talking about their nations’ experience with TIMSS Advanced.

The AAAS is one the world’s largest general scientific society, and one of the premier science organizations in the world. This year’s meeting brought together several thousand scientists, educators, journalists, and policy makers from some 50 countries.

O’Brien ‘11 and Barringer ‘11 Present at American Astronomical Society Meeting

Katelyn O’Brien, ’11, and Daniel Barringer, ’11, presented posters about their research at the 217th meeting of the American Astronomical Society meeting in Seattle, WA, in January.

Katie O’Brien ‘11 with her AAS Poster
Katelyn presented results from her senior thesis project with Associate Professor Rebecca Koopmann, ’89. Entitled “SMARTS Hα
Observations Of ALFALFA Gas-rich Galaxies In NGC 5846″, the poster described Katelyn’s analysis of star formation from images of galaxies obtained at the Cerro Tololo National Observatory in Chile through Union’s participation in the Small and Moderate Aperture Research Telescope System (SMARTS) consortium. Katelyn is pursuing a major in physics and minors in astrophysics and Spanish.

 

Danny Barringer ‘11 with his AAS Poster
Daniel presented results from his Summer 2010 Research Experience for Undergraduates (REU) summer project at the Kitt Peak National Observatory near Tucson, AZ. Daniel worked with Connie Walker of the National Optical Astronomy Observatory on the “Effects Of Light Pollution On The Movements Of Leptonycteris Curasoae Yerbabuenae In
The Tucson Area.” Daniel used data from the GLOBE at Night project and telemetry-tracking data to study the effects of light pollution on the flight paths of the lesser long-nosed bats between their day roosts and night foraging areas around the city of Tucson, AZ, finding that these bats are able to tolerate a fair degree of urbanization. Daniel was one of 6 students selected from a pool of 157 applicants from across the US to be awarded an REU internship at Kitt Peak in summer 2010. Daniel is a physics major and astrophysics minor.

The American Astronomical Society is the major organization of professional astronomers in North America.

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