Skip to main content

Ever wondered how lasers work? Here’s everything you need to know

Lasers! Clearly they are awesome — but how do they work, exactly? Why aren’t we all carrying them around in our pockets? Well, believe it or not, you probably are — thanks to modern electronics. Here’s the story of how a laser (light amplification by stimulated emission of radiation) operates, and what it does when it hits an object.

It’s all about electronsGreen Laser

Recommended Videos

Let’s spend a little time back in physics class: A laser owes its existence to electrons, which you may remember are those energetic particles that hover/exist around an atom, forming its “shell.”

Some electrons have the ability to absorb energy from outside sources and jump to higher-energy orbits, at least temporarily. However, the electrons quickly return to their normal orbits, and release the extra energy they used, which then ripples outside of the atom.

Electrons do this all the time—it’s how most radiation is created! Switch on a flashlight, and there’s a bunch of electrons cascading energy levels all over the place. But the reason that your flashlight is not a powerful laser beam (sorry) is that those electrons aren’t in sync. Instead, they hop all over the place, release energy randomly, and are hardly ever at the same wavelength or the same timing. In fact, electrons seem to naturally disperse their wavelengths and timing in these situations, which makes accidental lasers almost—but not entirely—impossible.

When creating a laser, engineers have to act like orchestra conductors for an innumerable number of electrons, getting them all to gain energy and release it in sync. When successful, this creates a coherent stream of photons that all move in the same manner, at the same time, in the same direction…and a laser is born. This happens thanks to a carefully constructed process and the right materials, which we will talk about in the next section!

Anatomy of a modern laser

Lasers come in all sizes, from tiny little lasers in microchips to vast lasers in science research facilities. However, most can be broken down into three very important parts that allow the laser to function.

Energy source: First, lasers require an energy source (also called pump sources or excitation mechanisms) to pump energy into the laser so that its electrons have a lot of juice to work with. There are several different popular types of energy sources, including direct electrical discharges, chemical reactions, and powerful sources of light like flash lamps.

Medium: The medium (typically called the gain medium or laser medium) is where the energy is directed. Its job is to gather that energy, get its electrons to jump around like crazy, and emit powerful bursts of light that are ready to be formed into a laser. Mediums cover a wide range of materials: Some are liquids, some are gases, and some are crystalline solids. Even a humble semiconductor can act as a laser medium.

Optical cavity: The optical cavity or resonator takes all the light released by the medium and focuses it. In the classic laser setup, it uses two mirrors to bounce that light back and forth to sync up the pulses, amplifying the energy and routing it toward a small opening where the laser is directed.

What happens when a laser hits something

In the marge towards the next most powerful lasers, things should only get more exciting.
Image used with permission by copyright holder

When a laser strikes a material, it acts just like other radiation: Some is absorbed, some is reflected, and some may pass through or be transmitted. But that doesn’t tell us much about what a particular, focused laser actually does to the material, so let’s take a closer look at several major categories of practical laser uses, and how they work.

Illumination: In this case, lasers are simply used to illuminate something that’s hard to see. That’s right, sometimes even the trusty flashlight won’t do, especially at very long distances — or when teachers really want to use a laser pointer. And yes, this can be dangerous.

Reflection: When lasers focus on reflection, they are typically transmitting information. The best example here is an optical disk drive found in Blu-ray players, computers, and so on. However, there are many smart device applications too.

Pyrolitic/photolytic reaction: Here, the laser is generally intended to change something…destructively. Pyrolitic versions heat a material, usually to melt it (and hey, sometimes zap birds). Photolytic versions break down chemical bonds within a material to accomplish similar goals.

Transmission: Here the laser is designed to pass down a code that encases valuable data, as in fiber optics.

State change: This is sort of a catch-all category, but in a number of cases the purpose of the laser is to change the material or change itself into a different type of energy (without burning anything). In this case, the material absorbs the laser and then undergoes an interesting transformation. For example, some lasers turn light into sound. Many such devices have valuable applications in everyday engineering.

Tyler Lacoma
If it can be streamed, voice-activated, made better with an app, or beaten by mashing buttons, Tyler's into it. When he's not…
The Ioniq 5 is once again eligible for the $7,500 tax credit
2025 Hyundai Ioniq 5

After a brief and confusing absence, the Hyundai Ioniq 5 is once again eligible for the full $7,500 federal tax credit — and this time, it's sticking around (at least for now). So, what happened? Let’s unpack the ride.

The Ioniq 5, a sleek and tech-savvy electric crossover, initially made headlines not just for its design, but for being built at Hyundai’s brand-new Metaplant in Georgia. That domestic assembly qualified it for the EV tax credit under the Inflation Reduction Act (IRA), which requires vehicles to be made in North America with batteries sourced from trade-friendly countries. But early in 2025, the Ioniq 5 vanished from the list. Why? Likely due to its battery packs, which were then still being sourced from SK On’s Hungarian facility.

Read more
Sebastian Stan lays out Bucky’s future after Thunderbolts
Sebastian Stan in Thunderbolts.

There are some spoilers ahead for the ending of Marvel's Thunderbolts. Stop reading now if you don't want to be spoiled.

Earlier this year, Captain America: Brave New World briefly introduced a new direction for James "Bucky" Barnes, a character Sebastian Stan has been playing since 2011 in Captain America: The First Avenger. In Brave New World, the former Winter Soldier apparently retired from being a reformed hero and went into politics by running for Congress. Thunderbolts reveals that Bucky won his election to the House of Representatives. But his stay in Congress was short.

Read more
Jeep Compass EV breaks cover—but will it come to the U.S.?
jeep compass ev us newjeepcompassfirsteditionhawaii  4

Jeep just pulled the wraps off the all-new Compass EV, and while it’s an exciting leap into the electric future, there's a catch—it might not make it to the U.S. anytime soon.
This is a brand new electric version of the Jeep Compass, and being built on Stellantis' STLA platform—the same architecture underpinning models like the Peugeot E-3008 and E-5008—it looks much slicker and packs a lot more inside than previous versions of the Compass.
Let’s start with what’s cool: the new Compass EV is packing up to 404 miles of range on a single charge, a 74 kWh battery, and fast-charging that gets you from 20% to 80% in about 30 minutes. Not bad for a compact SUV with Jeep's badge on the nose.
There are two versions: a front-wheel-drive model with 213 horsepower and a beefier all-wheel-drive version with 375 horsepower. That AWD setup isn’t just for looks—it can handle 20% inclines even without front traction, and comes with extra ground clearance and better off-road angles. In short, it’s still a Jeep.
The design's been refreshed too, and inside you’ll find the kind of tech and comfort you’d expect in a modern EV—sleek, smart, and ready for both city streets and dirt trails.
But here’s the thing: even though production starts soon in Italy, Jeep hasn’t said whether the Compass EV is coming to America. And the signs aren’t promising.
Plans to build it in Canada were recently put on hold, with production now delayed until at least early 2026. Some of that might have to do with possible U.S. tariffs on Canadian and Mexican vehicles—adding a layer of uncertainty to the whole rollout.
According to Kelley Blue Book, a Stellantis spokesperson confirmed that the company has “temporarily paused work on the next-generation Jeep Compass, including activities at” the Canadian plant that was originally meant to build the model. They added that Stellantis is “reassessing its product strategy in North America” to better match customer needs and demand for different powertrain options.
So while Europe and other markets are gearing up to get the Compass EV soon, American drivers might be left waiting—or miss out entirely.
That’s a shame, because on paper, this electric Jeep hits a lot of sweet spots. Let’s just hope it finds a way over here.

Read more