Briefly about lasers

Today, this light-based technology is nearly everywhere, in various aspects of our lives—in grocery store scanners, internet connectivity, rearview cameras in cars, medical devices, computers, and weapons. Whether you realize it or not, you interact with lasers every day. They helped build the modern, deeply interconnected world we live in.

The word “laser” is actually an abbreviation for “amplification of light through continuous emission of radiation.” Lasers work by causing energetic particles to vibrate or “oscillate” in synchrony; This means that the peaks and troughs of the light waves they emit are aligned (synchronized). Imagine a large number of people walking in an orderly manner compared to the chaotic crowds of people in a town square. This highlights the advantages of laser light over the inconsistent white light we are accustomed to.

When electrons in vibrationally synchronized atoms reach their highest energy state, they suddenly bounce back together to a lower energy state, emitting a special form of light in the process. The laser device then cleans this light by reflecting it between two mirrors before use. This is the light you see when it comes from a laser pointer, for example.

The basic physics underlying laser technology has been known for more than a century. The theory was first proposed by Albert Einstein in 1917. But it took almost four decades for researchers to put these theoretical ideas into practice.

what happened before

Before lasers, there were masters, a similar technology that used microwaves instead of visible light. The first functional maser was built in 1954 by a group of scientists from Columbia University. This device used a beam of high-energy ammonia molecules and a hollow body called a resonance cavity to cause microwaves to be emitted together. But the output power was too small; it was only around 10 nanowatts. This is a billion times less than the power required to turn on a regular light bulb. By contrast, the most powerful lasers on Earth can produce up to 10 petawatts, or about one-tenth the power of the Sun.

To create a more powerful maser, scientists began studying different frequencies of the electromagnetic spectrum. In 1960, the “optical maser”, which became “laser”, was born. Not all lasers operate in the visible light spectrum, but they all use frequencies above microwave radiation.

Lasers have many advantages over masers. In addition to packing more energy into the beam due to shorter electromagnetic wavelengths, lasers are easier to make and more precisely controlled. Although lasers are sometimes used for things like radio telescopes and deep space communications, lasers are much more common today.

what’s next

The future of laser technology looks no less cloudless. Some researchers are exploring the potential to image exoplanets far beyond our solar system. Scientists are also working on a project to miniaturize lasers to make data centers smaller and more energy efficient, thus reducing greenhouse gas emissions.

But this technology may have applications that we haven’t even imagined yet. Today, the uses of lasers are limited only by your imagination.