Beaming in on lasers

May 13, 2010

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Laser creator was ‘a natural inventor’
It took only $50,000, the help of one part-time lab assistant and nine months for Ted Maiman to make history by creating the world’s first laser.

He successfully demonstrated the device now used in everything from eye surgery to grocery store scanners in California on May 16, 1960—50 years ago this week.

"Ted was a natural inventor, a seasoned physicist and engineer, who worked from the age of 10 in his father’s electrical shop," says SFU engineering professor Andrew Rawicz, who is writing a book about his friend and mentor. "Even at that young age (he) often helped customers on his own.

"Not long before his invention, high radio frequencies were made coherent with the advent of radar, so it was only natural to try to go to much higher frequencies—for example, using light. Ted, along with many other scientists, joined the race.

"He started about a year later than the Bell Lab guys, but he was simply better."

Maiman later moved to Vancouver with his wife Kathleen and ultimately became an adjunct professor at SFU, where he and Rawicz became friends. The laser pioneer, who died in 2007, was nominated three times for a Nobel Prize.

"Ted wasn’t so much an academic—his joy was making things," says Rawicz, who collaborated with Maiman to develop a biophotonics program at SFU.

"He liked to get his hands into things. He was always looking to create some kind of spark. His last project was a vertical start airplane—nothing even close to a laser."

Maiman’s original laser will be demonstrated May 16 at the end of Laser Celebration 2010 at SFU’s Vancouver campus.

An invention that changed the world
The heart of Maiman’s laser—an acronym for light amplification by stimulated emission of radiation—is a bar of synthetic ruby, with a mirror at each end, one of which is transparent enough to let light pass through it.

A flash tube—which Maiman acquired from a photographic supply catalogue—is coiled around the bar.

"Ordinary light such as that produced from an incandescent light bulb is ‘incoherent,’ with every colour of the rainbow radiating out in different directions," explains SFU physicist Steve Dodge.

But a laser generates "coherent" light, which means its waves move in one direction and at the same wavelength, producing a powerful monochromatic or single-coloured beam.

"This coherent light is created when incoherent light is flashed into the ruby rod, ‘exciting’ the ruby’s electrons to a higher energy level," says Dodge.

"The electrons quickly return to their stable low-energy state while releasing photons of a single wavelength. As the light rays bounce between the mirrors at each end, they stimulate further light emission from other excited atoms.

"This process builds up to produce an intense beam of coherent light that emerges through the partially transparent mirror."

More than 450 Lower Mainland Grade 8 students have attended SFU’s free Lasers In Action science workshops last semester, and more are planned for the fall.

Laser Jell-O shots thrill kids
Physics instructor Rachel Moll spent a lot of time this spring making Jell-O.

That’s because shooting laser beams through narrow bars of the gelatin dessert is a great way to teach Grade 8 kids about light—which is what Moll has been doing all semester during SFU’s free Lasers In Action science workshops.

Lasers In Action is part of LaserFest, a year-long international celebration of the laser’s 50th anniversary.

More than 450 students attended the dozen two-hour Burnaby campus workshops, using lasers in hands-on experiments to learn about reflection, refraction and the nature of electromagnetic radiation.

The kids particularly enjoyed "creating optical mazes from mirrors and glass and using Jell-O to model how light travels in a fiber optic cable," says Moll.

She plans to continue the workshops this fall along with graduate and undergraduate student volunteers and other physics department staff.

Moll and senior chemistry lecturer Sophie Lavieri organized the program, which was conceived by physics professor Nancy Forde and sponsored by the science faculty’s Science in Action outreach program.

The program received support from a variety of sponsors including a $7,000 grant from the international optical engineering society, SPIE.

Laser Blazers

Andrew Rawicz
Biomedical engineering physicist Andrew Rawicz has been using laser light in his research into minimally invasive diagnostic techniques and photodynamic therapies for cancer. "Ted Maiman, inventor of the laser, had always wanted to see it applied in medicine," says Rawicz. "We’re now creating the Maiman Foundation to support further research into biophotonics, the study of using light in medical diagnostics and treatment.

Nancy Forde
Physicist Nancy Forde uses laser "tweezers" to grab and stretch single proteins and DNA molecules. The optical tweezers focus laser light through a microscope objective lens. At the focus, microscopic particles can be "trapped" (held stable, in solution) and the forces acting on them can be probed. Her research group is using these particles as handles to stretch single molecules. Forde aims to relate the sequence of proteins to their mechanical function, which may provide insight into the mechanisms of connective-tissue diseases.

Jeff McGuirk
Physicist Jeff McGuirk uses lasers in his atomic physics lab to cool and trap the gases of atoms. Scattering intense laser light off the atoms exerts enough force to cool the gases to a few millionths of a degree above absolute zero. The cooled gases stop behaving like ordinary room-temperature gases and exhibit a new state that allows McGuirk to study quantum mechanics—how objects behave when they become very small and/or very cold. Quantum mechanics is becoming important, says McGuirk, because "as electronics become smaller and smaller, classical physics will no longer be able to describe their behaviour."

Steve Dodge
Similar to the frames of a motion picture, physicist Steve Dodge’s research group is using laser pulses to make a rapid sequence of electrical measurements, limiting the time of observation to a few millionths of a billionth of a second. With these ultrafast "movies" of electronic behaviour in solids, they are getting a better picture of how different materials conduct electricity and what factors limit that conduction. Their work may lead to new electronic materials for use in power lines, consumer electronics and electronic communications.

Jeremy Venditti
Geographer Jeremy Venditti is trying to understand the role that turbulence plays in riverbed deposits and erosion. He recently received a $1-million Canada Foundation for Innovation grant to purchase new instruments that use laser beams and sheets of laser light to measure the velocity and turbulence in fluid flows. "This new equipment makes my laboratory the best-equipped in Canada for studying turbulent flows and sediment transport," he says.

SFU a laser safety pioneer
Rapid advances in laser technology are expanding its use in a variety of fields, yet its potential hazards—particularly serious eye damage—are not always recognized. SFU established a laser safety program 10 years ago to ensure the safe use of lasers on campus. And this year the Radiation Safety Office is planning to offer a new course to train non-university laser users who are interested in becoming laser-safety officers for their organizations. Radiation safety advisor Susan Yeung says if the plan goes ahead, SFU would be the first academic institution in B.C. to offer such training to external organizations.


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