Lasers: Putting Light To Work

Oct 23, 2018 By Alexis J, Writer Intern
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Did you know that laser is not a word, but an acronym? It stands for "Light Amplification by the Stimulation Emission of Radiation".

The first laser was invented in the 1960s and the technology is still being improved more than 50 years later.

The 2018 Nobel Prize in Physics was recently awarded to three physicists, Arthur Ashkin, Gerard Morou, and Donna Strickland, for their work with lasers to create optical tweezers and ultra-short, high-intensity laser pulses. This year’s Nobel Prize in Physics was unique in that it was awarded to a female for only the third time in 117 years!

What Are Lasers?

Lasers are very powerful beams of light that function by manipulating electrons. Electrons are negatively charged particles that reside within atoms- the particles that make up all of matter.

Electrons are associated with different energy levels within atoms. When electricity flows through an atom, the electrons are excited and their energy level rises. Then, as the electricity dissipates, the electrons drop back to their original energy levels and release a photon of light, or energy. A specific change in energy level of an electron causes a specific wavelength and color of light to be emitted.

Lasers move electrons through specific changes in energy levels to create a monochrome beam of light -- in other words one specific color/wavelength.

Putting Light To Work

Half of the Nobel Prize was awarded to Arthur Ashkin for his work in creating a tool called Optical Tweezers.

Optical Tweezers hold an object in place using just light. This tool allows scientists to manipulate very small objects such as cells and even individual molecules. The high intensity of a laser beam causes an object to be pushed towards the center of the beam and held there. Optical Tweezers are largely applicable in the field of biology, allowing scientists to observe and manipulate small biological objects, such as bacteria, without inflicting any harm on them.

The other half of this year’s Nobel Prize in Physics was shared by Gerard Morou and Donna Strickland. They created lasers which could generate a more powerful burst of energy by packing more photons, or light, in a smaller amount of space. This form of laser that emits energy in a quick, short and intense burst is known as "chirped pulse amplification." The technology is used for lasik eye surgery in which part of the eye is reshaped to correct for vision issues.

While Optical Tweezers and Chirped Pulse Amplification both have incredible potential in biological applications, you probably do not realize how frequently lasers are used in daily life. They are used in the military for laser targeting, in the medical field for cancer treatment, and in the industry for laser etching, welding, and drilling.

Even the barcode reader at the grocery store uses lasers. As you go about your week, keep an eye out for the use of lasers in places you would not normally notice.

Sources: NYTimes, Forbes, NPR, physics4kids