(Not the actual laser, just a cool looking one.)
"Researchers have set a new record for the rate of data transfer using a single laser: 26 terabits per second.
At those speeds, the entire Library of Congress collections could be sent down an optical fibre in 10 seconds.
The trick is to use what is known as a "fast Fourier transform" to unpick more than 300 separate colours of light in a laser beam, each encoded with its own string of information.
The technique is described in the journal Nature Photonics."
You may be asking: "What does this have to do with rocketry?" First of all, everything in the world has something to do with rocketry, so stop asking questions like that. But more specifically, lasers are a useful method of deep space communication. Particularly for missions past 100 au, and interstellar missions. Furthermore, lasers can be a useful way to communicate with other lifeforms around the galaxy. The Mercury Messenger mission was able to send a laser pulse over a distance of about 25 million km. This was received on Earth, well over a minute later.
An article on laser space communication.