Tag Archives: lasers

Quantum guitar music

The sound quality the physicists at the US National Institute of Standards and Technology (NIST) have achieved is quite good compared to carbon nanotube radio. If you’re curious, the audio file is embedded in both the American Institute of Physics (AIP) June 18, 2019 news release (and in the copy on EurekAlert),

It sounds like an old-school vinyl record, but the distinctive crackle in the music streamed into Chris Holloway’s laboratory is atomic in origin. The group at the National Institute for Standards and Technology, Boulder, Colorado, spent a long six years finding a way to directly measure electric fields using atoms, so who can blame them for then having a little fun with their new technology?

“My vision is to cut a CD in the lab — our studio — at some point and have the first CD recorded with Rydberg atoms,” said Holloway. While he doesn’t expect the atomic-recording’s lower sound quality to replace digital music recordings, the team of research scientists is considering how this “entertaining” example of atomic sensing could be applied in communication devices of the future.

“Atom-based antennas might give us a better way of picking up audio data in the presence of noise, potentially even the very weak signals transmitted in deep space communications,” said Holloway, who describes his atomic receiver in AIP Advances, from AIP Publishing.

The atoms in question — Rydberg atoms — are atoms excited by lasers into a high energy state that responds in a measurable way to radio waves (an electric field). After figuring out how to measure electric field strength using the Rydberg atoms, Holloway said it was a relatively simple step to apply the same atoms to record and play back music — starting with Holloway’s own guitar improvisations in A minor.

They encoded the music onto radio waves in much the same way cellphone conversations are encoded onto radio waves for transmission. The atoms respond to these radio waves, and in turn, the laser beams shined through the Rydberg atoms are affected. These changes are picked up on a photodetector, which feeds an electric signal into the speaker or computer — and voila! The atomic radio was born

The team used their quantum system to pick up stereo — with one atomic species recording the instrumental and another the vocal at two different sets of laser frequencies. They selected a Queen track — “Under Pressure” — to test if their system could handle Freddie Mercury’s extensive vocal range.

“One of the reasons for cutting stereo was to show that this one receiver can pick up two channels simultaneously, which is difficult with conventional receivers,” said Holloway, who explained that although it is the early days for atomic communications, there is potential to use this to improve the security of communications.

For now, Holloway’s team are staying tuned into atomic radio as they try to determine how weak a signal the Rydberg atoms can detect, and what data transfer speeds can be achieved.

They are not forgetting the atomic record they want to produce, with which they hope to inspire the next generation of quantum scientists.

Here’s a link to and a citation for the paper,

A “real-time” guitar recording using Rydberg atoms and electromagnetically induced transparency: Quantum physics meets music by Christopher L. Holloway, Matthew T. Simons, Abdulaziz H. Haddab, Carl J. Williams, and Maxwell W. Holloway. AIP Advances volume 9 (6), 065110 (2019) DOI: 10.1063/1.5099036 https://doi.org/10.1063/1.5099036 Open Published Online: 18 June 2019

This paper is open access and, if you want to hear the guitar music, click on the AIP news release or EurekAlert links at the top of this posting.

A coating for airplane windshields that mitigates laser intensity

Whether it’s done accidentally or with malice, blinding airplane pilots with lasers pointed at the windows of cockpits has become a serious problem. From the Lasers and aviation safety Wikipedia entry,

Pointing a laser at an aircraft can be hazardous to pilots[1] and has resulted in arrests, trials and jail sentences. It also results in calls to license or ban laser pointers.

A June 3, 2015 news item on Nanowerk describes a Lewis University technology that could help minimize this problem. (Lewis University is a private university located in the state of Illinois, US; Note: A link has been removed),

A recently published Journal of Aviation Technology and Engineering article (“Measuring the Effectiveness of Photoresponsive Nanocomposite Coatings on Aircraft Windshields to Mitigate Laser Intensity”) shows Lewis University researchers have created a coating for aircraft that reduces pilot distraction from laser attacks.

In [sic] 2013 study, Lewis University proved these laser attacks, which average around 3,750 incidents a year, can be a distraction to pilots and a potential safety hazard during critical phases of flight. As part of continued research on the matter, Lewis University recently developed a practical and economical solution through the use of photoresponsive nanocomposite coatings on aircraft windscreens.

The most recent study determined the application of the engineered films resulted in a reduction in laser intensity from 36-88 percent.

A June 2, 2015 Lewis University news release, which originated the news item, provides a bit more detail about the research (Note: Links have been removed),

The study was completed through collaboration of the Aviation, Physics and Chemistry departments at Lewis University. The Chemistry Department developed the photoselective coatings, and the Physics Department developed the apparatus to efficiently test the coatings while allowing safe viewings of laser illumination. The coatings were bench-tested in a laboratory prior to conducting field tests at the 200- and 500-foot distances.

I was unfamiliar with Lewis University so was happy to see the news release fill in a few blanks (Note: Links have been removed),

This research was sponsored, in part, by a grant from the Colonel Stephan S. and Lyla Doherty Center for Aviation and Health Research. The Doherty Center funds research and scholarly initiatives and provides opportunities for research experiences for students with faculty mentors. Investigators supported by the Doherty Center have focused on several areas, such as cardiac therapy, wound management, flight deck laser illumination, the environment, diabetes, MRSA, and alternative fuels for aviation.

Since 1932, Lewis University has led the field of aviation education by preparing students from around the world to succeed in the aviation industries. An on-site airport, experienced and industry-leading faculty, personalized learning, degree programs that provide you with specialized experience and a well-rounded business, management and liberal arts education have made Lewis University’s aviation program one of the most respected in Illinois.

Lewis University is a Catholic university in the Lasallian tradition offering distinctive undergraduate and graduate programs to more than 6,700 traditional and adult students. Lewis offers multiple campus locations, online degree programs, and a variety of formats that provide accessibility and convenience to a growing student population. Sponsored by the De La Salle Christian Brothers, Lewis prepares intellectually engaged, ethically grounded, globally connected, and socially responsible graduates. The seventh largest private not-for-profit university in Illinois, Lewis has been nationally recognized by The Princeton Review and U.S. News & World Report. Visit www.lewisu.edu for further information.

Here’s a link to and a citation for the paper,

Measuring the Effectiveness of Photoresponsive Nanocompsite Coatings on Aircraft Windshields to Mitigate Laser Intensity by Ryan S. Phillips, Hubert K. Bilan, Zachary X. Widel, Randal J. DeMik, Samantha J. Brain, Matthew Moy, Charles Crowder, Stanley L. Harriman, James T. O’Malley III, Joseph E. Burlas, Steven F. Emmert, & Jason J. Keleher. Journal of Aviation Technology and Engineering (2015): Vol. 4: Iss. 2, Article 5. http://dx.doi.org/10.7771/2159-6670.1105

This paper is open access.

Outer space telescopes made of micro- and nanoparticles (smart dust)

Scientists at Rochester Institute of Technology (RIT is located in New York state) are working on a project that would see ‘smart dust’ used as a telescope in outer space. From a Dec. 1, 2014 news item on phys.org,

Telescope lenses someday might come in aerosol cans. Scientists at Rochester Institute of Technology and the NASA [ National Aeronautics and Space Administration] Jet Propulsion Laboratory are exploring a new type of space telescope with an aperture made of swarms of particles released from a canister and controlled by a laser.

These floating lenses would be larger, cheaper and lighter than apertures on conventional space-based imaging systems like NASA’s Hubble and James Webb space telescopes, said Grover Swartzlander, associate professor at RIT’s Chester F. Carlson Center for Imaging Science and Fellow of the Optical Society of America. Swartzlander is a co-investigator on the Jet Propulsion team led by Marco Quadrelli.

A Dec. 1, 2014 RIT news release by Susan Gawlowicz, which originated the news item, describes the NASA project and provides more details about the technology,

NASA’s Innovative Advanced Concepts Program is funding the second phase of the “orbiting rainbows” project that attempts to combine space optics and “smart dust,” or autonomous robotic system technology. The smart dust is made of a photo-polymer, or a light-sensitive plastic, covered with a metallic coating.

“Our motivation is to make a very large aperture telescope in space and that’s typically very expensive and difficult to do,” Swartzlander said. “You don’t have to have one continuous mass telescope in order to do astronomy—it can be distributed over a wide distance. Our proposed concept could be a very cheap, easy way to achieve large coverage, something you couldn’t do with the James Webb-type of approach.”

An adaptive optical imaging sensor comprised of tiny floating mirrors could support large-scale NASA missions and lead to new technology in astrophysical imaging and remote sensing.

Swarms of smart dust forming single or multiple lenses could grow to reach tens of meters to thousands of kilometers in diameter. According to Swartzlander, the unprecedented resolution and detail might be great enough to spot clouds on exoplanets, or planets beyond our solar system.

“This is really next generation,” Swartzlander said. “It’s 20, 30 years out. We’re at the very first step.”

Previous scientists have envisioned orbiting apertures but not the control mechanism. This new concept relies upon Swartzlander’s expertise in the use of light, or photons, to manipulate micro- or nano-particles like smart dust. He developed and patented the techniques known as “optical lift,” in which light from a laser produces radiation pressure that controls the position and orientation of small objects.

In this application, radiation pressure positions the smart dust in a coherent pattern oriented toward an astronomical object. The reflective particles form a lens and channel light to a sensor, or a large array of detectors, on a satellite. Controlling the smart dust to reflect enough light to the sensor to make it work will be a technological hurdle, Swartzlander said.

Two RIT graduate students on Swartzlander’s team are working on different aspects of the project. Alexandra Artusio-Glimpse, a doctoral student in imaging science, is designing experiments in low-gravity environments to explore techniques for controlling swarms of particle and to determine the merits of using a single or multiple beams of light.

Swartzlander expects the telescope will produce speckled and grainy images. Xiaopeng Peng, a doctoral student in imaging science, is developing software algorithms for extracting information from the blurred image the sensor captures. The laser that will shape the smart dust into a lens also will measure the optical distortion caused by the imaging system. Peng will use this information to develop advanced image processing techniques to reverse the distortion and recover detailed images.

“Our goal at this point is to marry advanced computational photography with radiation-pressure control techniques to achieve a rough image,” Swartzlander said. “Then we can establish a roadmap for improving both the algorithms and the control system to achieve ‘out of this world’ images.”

You can find out more about NASA’s Orbiting Rainbows project here.

I just mentioned rainbows and optics with regard to Robert Grosseteste, a 13th century cleric who ‘unwove’ rainbows, in a Dec. 1, 2014 posting (scroll down about 60% of the way).

Ethereal optical cables

It’s a gobsmacking idea but here’s what scientist Howard Milchberg wants to accomplish (from a July 22, 2014 University of Maryland (UMD) news release (also on EurekAlert) [written by Brian Doctrow]),

Imagine being able to instantaneously run an optical cable or fiber to any point on earth, or even into space. That’s what Howard Milchberg, professor of physics and electrical and computer engineering at the University of Maryland, wants to do.

In a paper published today in the July 2014 issue of the journal Optica, Milchberg and his lab report using an “air waveguide” to enhance light signals collected from distant sources. These air waveguides could have many applications, including long-range laser communications, detecting pollution in the atmosphere, making high-resolution topographic maps and laser weapons.

Here’s an image illustrating the first step to achieving ‘ethereal cables’, an air waveguide,

Caption: This is an illustration of an air waveguide. The filaments leave 'holes' in the air (red rods) that reflect light. Light (arrows) passing between these holes stays focused and intense. Credit: Howard Milchberg

Caption: This is an illustration of an air waveguide. The filaments leave ‘holes’ in the air (red rods) that reflect light. Light (arrows) passing between these holes stays focused and intense.
Credit: Howard Milchberg

Here’s more about precursor research into creating air waveguides, from the news release,

Milchberg showed previously that these filaments heat up the air as they pass through, causing the air to expand and leaving behind a “hole” of low-density air in their wake. This hole has a lower refractive index than the air around it. While the filament itself is very short lived (less than one-trillionth of a second [less than a picosecond]), it takes a billion times longer for the hole to appear. It’s “like getting a slap to your face and then waiting, and then your face moves,” according to Milchberg, who also has an appointment in the Institute for Research in Electronics and Applied Physics at UMD.

On Feb. 26, 2014, Milchberg and his lab reported in the journal Physical Review X that if four filaments were fired in a square arrangement, the resulting holes formed the low-density wall needed for a waveguide. When a more powerful beam was fired between these holes, the second beam lost hardly any energy when tested over a range of about a meter. Importantly, the “pipe” produced by the filaments lasted for a few milliseconds, a million times longer than the laser pulse itself. For many laser applications, Milchberg says, “milliseconds [thousandths of a second] is infinity.”

The latest work brings Milchberg a step closer to using air waveguides as cables for lasers (from the news release),

Because light loses intensity with distance, the range over which such tasks can be done is limited. Even lasers, which produce highly directed beams, lose focus due to their natural spreading, or worse, due to interactions with gases in the air. Fiber-optic cables can trap light beams and guide them like a pipe, preventing loss of intensity or focus.

Typical fibers consist of a transparent glass core surrounded by a cladding material with a lower index of refraction. When light tries to leave the core, it gets reflected back inward. But solid optical fibers can only handle so much power, and they need physical support that may not be available where the cables need to go, such as the upper atmosphere. Now, Milchberg’s team has found a way to make air behave like an optical fiber, guiding light beams over long distances without loss of power.

Milchberg’s air waveguides consist of a “wall” of low-density air surrounding a core of higher density air. The wall has a lower refractive index than the core—just like an optical fiber. In the Optica paper, Milchberg, physics graduate students Eric Rosenthal and Nihal Jhajj, and associate research scientist Jared Wahlstrand, broke down the air with a laser to create a spark. An air waveguide conducted light from the spark to a detector about a meter away. The researchers collected a strong enough signal to analyze the chemical composition of the air that produced the spark.

The signal was 1.5 times stronger than a signal obtained without the waveguide. That may not seem like much, but over distances that are 100 times longer, where an unguided signal would be severely weakened, the signal enhancement could be much greater.

Milchberg creates his air waveguides using very short, very powerful laser pulses. A sufficiently powerful laser pulse in the air collapses into a narrow beam, called a filament. This happens because the laser light increases the refractive index of the air in the center of the beam, as if the pulse is carrying its own lens with it.

Because the waveguides are so long-lived, Milchberg believes that a single waveguide could be used to send out a laser and collect a signal. “It’s like you could just take a physical optical fiber and unreel it at the speed of light, put it next to this thing that you want to measure remotely, and then have the signal come all the way back to where you are,” says Milchberg.

First, though, he needs to show that these waveguides can be used over much longer distances—50 meters at least. If that works, it opens up a world of possibilities. Air waveguides could be used to conduct chemical analyses of places like the upper atmosphere or nuclear reactors, where it’s difficult to get instruments close to what’s being studied. The waveguides could also be used for LIDAR, a variation on radar that uses laser light instead of radio waves to make high-resolution topographic maps.

Here are links to and citations for both papers from Milchberg’s research team,

Demonstration of Long-Lived High-Power Optical Waveguides in Air by N. Jhajj, E. W. Rosenthal, R. Birnbaum, J. K. Wahlstrand, and H. M. Milchberg. Physical Review X: http://dx.doi.org/10.1103/PhysRevX.4.011027 Published Feb. 26, 2014

Collection of remote optical signals by air waveguides by E. W. Rosenthal, N. Jhajj, J. K. Wahlstrand, and H. M. Milchberg. Optica, Vol. 1, Issue 1, pp. 5-9 (July 2014) http://dx.doi.org/10.1364/OPTICA.1.000005

Both papers are open access.

Move over laser—the graphene/carbon nanotube spaser is here, on your t-shirt

This research graphene/carbon nanotube research comes from Australia according to an April 16, 2014 news item on Nanowerk,

A team of researchers from Monash University’s [Australia] Department of Electrical and Computer Systems Engineering (ECSE) has modelled the world’s first spaser …

An April 16, 2014 Monash University news release, which originated the new item, describes the spaser and its relationship to lasers,,

A new version of “spaser” technology being investigated could mean that mobile phones become so small, efficient, and flexible they could be printed on clothing.

A spaser is effectively a nanoscale laser or nanolaser. It emits a beam of light through the vibration of free electrons, rather than the space-consuming electromagnetic wave emission process of a traditional laser.

The news release also provides more details about the graphene/carbon nanotube spaser research and the possibility of turning t-shirts into telephones,

PhD student and lead researcher Chanaka Rupasinghe said the modelled spaser design using carbon would offer many advantages.

“Other spasers designed to date are made of gold or silver nanoparticles and semiconductor quantum dots while our device would be comprised of a graphene resonator and a carbon nanotube gain element,” Chanaka said.

“The use of carbon means our spaser would be more robust and flexible, would operate at high temperatures, and be eco-friendly.

“Because of these properties, there is the possibility that in the future an extremely thin mobile phone could be printed on clothing.”

Spaser-based devices can be used as an alternative to current transistor-based devices such as microprocessors, memory, and displays to overcome current miniaturising and bandwidth limitations.

The researchers chose to develop the spaser using graphene and carbon nanotubes. They are more than a hundred times stronger than steel and can conduct heat and electricity much better than copper. They can also withstand high temperatures.

Their research showed for the first time that graphene and carbon nanotubes can interact and transfer energy to each other through light. These optical interactions are very fast and energy-efficient, and so are suitable for applications such as computer chips.

“Graphene and carbon nanotubes can be used in applications where you need strong, lightweight, conducting, and thermally stable materials due to their outstanding mechanical, electrical and optical properties. They have been tested as nanoscale antennas, electric conductors and waveguides,” Chanaka said.

Chanaka said a spaser generated high-intensity electric fields concentrated into a nanoscale space. These are much stronger than those generated by illuminating metal nanoparticles by a laser in applications such as cancer therapy.

“Scientists have already found ways to guide nanoparticles close to cancer cells. We can move graphene and carbon nanotubes following those techniques and use the high concentrate fields generated through the spasing phenomena to destroy individual cancer cells without harming the healthy cells in the body,” Chanaka said

Here’s a link to and a citation for the paper,

Spaser Made of Graphene and Carbon Nanotubes by Chanaka Rupasinghe, Ivan D. Rukhlenko, and Malin Premaratne. ACS Nano, 2014, 8 (3), pp 2431–2438. DOI: 10.1021/nn406015d Publication Date (Web): February 23, 2014
Copyright © 2014 American Chemical Society

This paper is behind a paywall.

Ian Bushfield weighs paper with his lasers

Café Scientifique Vancouver (Canada) will be holding a meeting on the subject of lasers and weighing paper at The Railway Club on the 2nd floor of 579 Dunsmuir St. (at Seymour St.) next Tuesday, from the Mar. 19, 2013 email announcement,

Our next café will happen on Tuesday March 26th, 7:30pm at The Railway Club. Our speaker for the evening will be Ian Bushfield.

The title and abstract for his café is:

“Weighing Paper With Lasers”

Until the 1990s, a narrow band of radiation in the far-infrared had remained largely unexplored. Terahertz radiation’s unique interaction with water molecules and weak interaction with most plastic and fabrics make it an ideal probe for a wide range of applications, from security scanners to death rays. One area of interest is in product testing and quality control. In this talk, Ian Bushfield will describe his masters of physics work in developing a technique to use terahertz radiation to obtain the thickness, weight, and water content of paper, for application in paper manufacturing. These non-contact sensors offer industry a way to improve accuracy and production speed by replacing sensors that rely on physical contact with paper reams. This work was supported by the NSERC Industrial Postgraduate Scholarship, SFU, and the Honeywell Vancouver Centre for Excellence.

We hope to see you there!

Ian Bushfield has his own website,

I am the executive director of the British Columbia Humanist Association and a passionate advocate for science outreach and education. I have recently completed an MSc in Physics and have a BSc in Engineering Physics. I have worked as a research assistant and as a science summer camp instructor.

I gather Bushfield will be focusing on the work he did for his master’s thesis (from Bushfield’s résumé page),

Master of Science in Physics, Simon Fraser University 2011

Given the description for his talk, I don’t imagine Bushfield will be discussing his interest in humanism although I’m sure he’ll be open to questions. I’ve found the meetings at the Railway Club to be pleasantly fueled by beer, burgers, and conversation about science and any other topics attendees care to raise. (Bushfield was last mentioned here in my Feb. 8, 2013 posting about Charles Darwin Day and the February 2013 Café Scientifique meeting.)

It’s a bird. It’s a plane. No, it’s a laser!

I couldn’t resist the Superman reference although it really should have been a Morpho butterfly or a jewel beetle reference since these are two other animals/insects that also display unusual optical properties courtesy of nanoscale structures.

Top: Male eastern bluebird (Sialia sialis, Turdidae). Credit: Ken Thomas (image in public domain). Published in Soft Matter, 2009, 5, 1792-1795. E.R. Dufresne et al., “Self-assembly of amorphous biophotonic nanostructures by phase separation.” Royal Society of Chemistry. http://dx.doi.org/10.1039/B902775K

According to the Oct. 12, 2011 news item on Nanowerk,

Researchers at Yale University are studying how two types of nanoscale structures on the feathers of birds produce brilliant and distinctive colors. The researchers are hoping that by borrowing these nanoscale tricks from nature they will be able to produce new types of lasers—ones that can assemble themselves by natural processes. The team will present their findings at the Optical Society’s (OSA) Annual Meeting, Frontiers in Optics (FiO) 2011, taking place in San Jose, Calif. next week. [It starts Sunday, Oct. 16, 2011.]

Devin Powell, in a May 13, 2011 article for Science News provides some additional detail,

The barbs of these feathers [from bluebirds, blue jays, and parrots] contain tiny pockets of air. Light striking the tightly packed air bubbles scatters, bringing out deep shades of blues and ultraviolet (which birds can see but humans can’t).

“Birds use these structures to create colors that they can’t make in other ways,” says Richard Prum, an  ornithologist at Yale University who discovered the mechanism behind this color.

To make a two-dimensional imitation of a bird feather, Yale physicist Hui Cao and her colleagues punched holes into a thin slice of gallium arsenide semiconductor. The holes were arranged like people in a crowd — somewhat haphazardly but with small-scale patterns that dictate roughly how far each hole is from its neighbor.

“The lesson we learned from nature is that we don’t need something perfect to get control,” says Cao, whose team describes their laser in the May 6 [2011] Physical Review Letters.

The latest work being presented is described this way in an Oct. 2011 news release (why aren’t people putting dates on their news releases????) from the Optical Society of America,

Inspired by feathers, the Yale physicists created two lasers that use this short-range order to control light. One model is based on feathers with tiny spherical air cavities packed in a protein called beta-keratin. The laser based on this model consists of a semiconductor membrane full of tiny air holes that trap light at certain frequencies. Quantum dots embedded between the holes amplify the light and produce the coherent beam that is the hallmark of a laser. The researchers also built a network laser using a series of interconnecting nano-channels, based on their observations of feathers whose beta-keratin takes the form of interconnecting channels in “tortuous and twisting forms.” The network laser produces its emission by blocking certain colors of light while allowing others to propagate. In both cases, researchers can manipulate the lasers’ colors by changing the width of the nano-channels or the spacing between the nano-holes.

What makes these short-range-ordered, bio-inspired structures different from traditional lasers is that, in principle, they can self-assemble, through natural processes similar to the formation of gas bubbles in a liquid. This means that engineers would not have to worry about the nanofabrication of the large-scale structure of the materials they design, resulting in cheaper, faster, and easier production of lasers and light-emitting devices.

Here’s an image of a ‘feather-based laser’,

Top: A laser based on feathers with the sphere-type nanostructure. This laser consists of tiny air holes (black) in a semiconductor membrane; each hole is about 77 nanometers across. (Scale bar = 5 micrometers.) Credit: Hui Cao Research Laboratory / Yale University.

As for the Morpho butterfly and jewel beetle, I last posted about gaining inspiration from these insects (biomimicry) in my May 20, 2011 posting in the context of some anti-counterfeiting strategies.

I first came across some of this work on the optical properties of nanostructures in nature in a notice about a 2008 conference on iridescence at Arizona State University. Here’s the stated purpose for the conference (from the conference page),

A unique, integrative 4–day conference on iridescent colors in nature, Iridescence: More than Meets the Eye is a graduate student proposed and organized conference supported by the Frontiers in Life Sciences program in Arizona State University’s School of Life Sciences. This conference intends to connect diverse groups of researchers to catalyze synthetic cross–disciplinary discussions regarding iridescent coloration in nature, identify new avenues of research, and explore the potential for these stunning natural phenomena to provide novel insights in fields as divergent as materials science, sexual selection and primary science education.

Lasers and Paul Corkum

The Canada Science and Technology Museum is going to be featuring a public talk by Paul Corkum (mentioned in my May 13, 2009 posting and my March 17, 2009 posting) about the past, the present, and the future for lasers. Titled, Catching Electrons with Light; Celebrating the past, present, and future of the laser in Canada, the event will be held on Jan. 20, 2011 at 7 pm. From the Museum’s event page,

Presentation by Dr. Paul Corkum, University of Ottawa and National Research Council of Canada

Laser technology, which celebrated its 50th anniversary in 2010, is undergoing a revolution. Extremely short laser pulses are providing a powerful new tool in the study of the smallest structures on Earth. The laser’s incredible speed is making it possible to “photograph” electrons, bonds breaking, or atoms rearranging themselves within molecules during a chemical reaction – the very essence of chemistry.

Dr. Paul Corkum of the University of Ottawa and the National Research Council of Canada will discuss recent advances in laser technology. Before the lecture, examine lasers from the Museum’s collection, as well as the National Research Council’s first laser, a recent major acquisition for the Museum. Dr. Alex Szabo of the NRC will be present to share how he and Dr. Boris Stoicheff developed the first Canadian laser in January 1961.

Admission is free. RSVP by January 19, 2011. rsvp@technomuses.ca

I’m glad to hear of this interesting event. I wish they’d webcast these things. It doesn’t have to be livestreamed; all they have to do is video the event and post it online afterwards so those of who don’t live in Ottawa can have access. Perhaps even that is just too expensive?