Liquid Lasers Challenge Fiber Lasers as the Basis of Future High-Energy Weapons
Despite a lot of progress in recent years, practical laser weapons that can shoot down planes or missiles are still a ways off. But a new liquid laser may be bringing that day closer.
Much of the effort in recent years has focused on high-power fiber lasers. These lasers usually[sic] specially doped coils of optical fibers to amplify a laser beam, and were in originally developed for industrial cutting and welding. Initially, fiber laser were dark horses in the Pentagon's effort to develop electrically powered solid-state laser weapons that began two decades ago. However, by 2013 the Navy was testing a 30-kilowatt fiber laser on a ship. Since then, their ability to deliver high-energy beams of excellent optical quality has earned fiber lasers the leading role in the current field trials of laser weapons in the 50- to 100-kilowatt class. But now aerospace giant Boeing has teamed with General Atomics—a defense contractor also known for research in nuclear fusion—to challenge fiber lasers in achieving the 250-kilowatt threshold that some believe will be essential for future generations of laser weapons. Higher laser powers would be needed for nuclear missile defense.
The challenging technology was developed to control crucial issues with high energy solid-state lasers: size, weight and power, and the problem of dissipating waste heat that could disrupt laser operation and beam quality. General Atomics "had a couple of completely new ideas, including a liquid laser. They were considered completely crazy at the time, but DARPA funded us," said company vice president Mike Perry in a 2016 interview. Liquid lasers are similar to solid-state lasers, but they use a cooling liquid that flows through channels integrated into the solid-state laser material. A crucial trick was ensuring that the cooling liquid has a refractive index exactly the same as that of the solid laser material. A perfect match of the liquid and solid could avoid any refraction or reflection at the boundary between them. Avoiding reflection or refraction in the the cooling liquid also required making the fluid flow smoothly through the channels to prevent turbulence.
(Score: 0) by Anonymous Coward on Sunday October 25 2020, @02:08PM (1 child)
Professor Hathaway: What are you looking at? You're laborers; you should be laboring. That's what you get for not having an education.
(Score: 0) by Anonymous Coward on Sunday October 25 2020, @10:52PM
Then maybe they can freeze them. "It's like lasing dynamite!"
(Score: 0) by Anonymous Coward on Sunday October 25 2020, @02:13PM
How convenient.
(Score: 1, Interesting) by Anonymous Coward on Sunday October 25 2020, @04:54PM (2 children)
Ok, been out of the game for a while and am slightly confused here, but when they say 'a Liquid Laser' are they talking about
i. A Dye Laser (oh!, those leaky connectors, those fun carcinogenic dye mixes...)
ii. A new solid-state Laser design using some froody new liquid cooling.
iii. A solid-state Laser pumped Dye Laser where you have a combined SS/Dye output beam and where the dye also acts as a circulatable coolant.
(Score: 2) by VLM on Sunday October 25 2020, @05:56PM (1 child)
Near as I can tell, your case 2.
I don't understand the problem with case 1. I'm so old I remember when tunable dye lasers were new, like in the 70s. There was a scientific american "amateur scientist" column on building your own liquid laser at home.
Here's a link to February 1970
https://www.scientificamerican.com/article/the-amateur-scientist-1970-02/ [scientificamerican.com]
"A tunable laser using organic dye is made at home for less than $75"
Yeah well inflation so more like $1500 now.
I have a cdrom from around the turn of the century of all amateur scientist columns I will have to examine this one.
Hard to believe that column is from fifty years and eight months ago.
In the context of hilarious article quotes, I guess more than half century old is "new" in comparison to somewhat older technologies such as "fire" and "that giant ass monolith from 2001"
(Score: 0) by Anonymous Coward on Sunday October 25 2020, @07:12PM
I worked in a couple of Universities and, being Mr Fixit, had to fix occasional problems with dye lasers, yes, there are dyes that aren't that bad, but the ones these lot were using back then...they were not so very nice, and then there were the solvents (poor plumbing material choices made for the leaky pipework...you'd have thought they'd check the new wondersolvent/dye combo wouldn't eat the pipework, wouldn't you?) it didn't help matters that one of the poor things was being used to research new dye/solvent combinations by a group of wannabe Death Star operators..fun times, and that (and a whole bunch of chemical lab horror stories and near misses..) is why I jumped ship to computers and IT..