New Kind of Laser Uses Tiny Particle Clumps To Generate Light (newscientist.com) 16
A new kind of laser uses tiny moving particles to produce beams of light. The laser is more programmable than standard lasers and the approach could be used to create visual displays that are sharp from all angles. New Scientist reports: Conventional lasers repeatedly bounce light between two mirrors until it becomes bright and focused. Riccardo Sapienza at Imperial College London and his colleagues have built a laser that uses particles that can arrange themselves to carry out a similar process. The new type of laser first requires the use of green light from a traditional laser. The researchers shine this light into a small glass box filled with a liquid solution containing particles of titanium oxide and silicon oxide. This warms up the silicon oxide particles and causes the titanium oxide particles to clump around them.
The green light then bounces between particles in the clump -- similarly to how light bounces between mirrors in conventional lasers -- until the clump itself starts to emit a laser beam, now in the color red. By nudging the particles into different positions with the green light, the team can program the properties of the light emitted by the laser, such as where in the device it originates from and how pure its color is. By comparison, conventional lasers can't be adjusted after manufacturing. The findings have been published in the journal Nature Physics.
The green light then bounces between particles in the clump -- similarly to how light bounces between mirrors in conventional lasers -- until the clump itself starts to emit a laser beam, now in the color red. By nudging the particles into different positions with the green light, the team can program the properties of the light emitted by the laser, such as where in the device it originates from and how pure its color is. By comparison, conventional lasers can't be adjusted after manufacturing. The findings have been published in the journal Nature Physics.
Great! (Score:2)
Re: (Score:2)
I swear they have them all set up backwards. They have a high-brightness mode for daytime and a dim mode for night. And they are all set up in reverse to blind you at night.
Everyone thinks brighter is safer and never think about contrast. These days, I can't even see the road when there's an emergency vehicle within 500 ft and when it's raining, the stoplight glare on the road is so bright I can't find the dividing lines between lanes.
Re: (Score:2)
This sounds like you have vision problems. Check with an optometrist.
Re: (Score:2)
Been to one very recently. No problems and no need for glasses. This is an issue with the real world. Bright lights cause pupils to constrict and prevent you from seeing dimmer objects. And the pupils don't dilate back instantly when the bright lights go away either.
Re: (Score:3)
Some people can see past headlights at night and some can't, and those who can't should carry a warning on their license, and get home before dark. This whole dependence on the car thing essentially means driving needs to be a right, but a lot of people can't safely drive in a lot of circumstances so that means that we're creating situations where people have to drive unsafely in order to participate in society.
My lady can't see at night while driving, so she structures her decisions to avoid it. I can, so
Re: (Score:2)
I can see fine at night. My low light vision is great. The brightness wars are the only thing different. Maybe it's the lights that need the warning/restriction. And especially ticketing improper HID lights (though these aren't even as bright as a police car pulling them over on the shoulder).
Re: (Score:2)
Tunable lasers? (Score:5, Informative)
Sure, those tunable lasers, which people who work with coherent optics, ought to be familiar with, are probably not "conventional" to people that don't work in the field. But they're certainly not unique as these have been a staple for spectroscopy applications where narrow output frequency/wavelength sweeps are used for a while.
Anyway, if this leads to simpler tunable lasers, as in easier to construct, operate, integrate into other systems, I certainly welcome it.
At the surface it looks like a neat new method that could bring tunable laser sources to many different applications where their "conventional" and usually bulky size used to be a prohibitive factor.
Re: (Score:2)
It seems that this research is designed from the start to create multiple pixels of color. I don't know about the wide application, but it sure seems like it's intended for displays or projection.
On the other hand, using a sweeping laser beam to draw a picture on emissive particles seems a little obsolete from the start.
Re: Tunable lasers? (Score:2)
Re: (Score:2)
Yeah, the display application does
Re: (Score:2)
Re: (Score:1)
I hate to think of the negative applications for this, but being tunable, does that mean it would be easy to make it adjust to frequencies not covered by protective filters? Would this kind of laser in a weapon system be that much more deadly because you could "modulate the frequency" to bypass coatings or protective measured that only covered some wavelengths, or were susceptible to some wavelengths?
Re: (Score:2)
In practice to weaponize a laser you need to generate a sufficiently high flux density at the target, via combination of optics and of course raw power output.
With this particular approach it doesn't sound like it generates a large "modulated" power output to begin with. Because first you need to pump your "dye medium" with a fairly powerful conventional laser in order to get the pumped "dye medium" lasing itself. This necessitates additional energy loss mechanism w
nonpaywalled link (Score:5, Informative)
Re: (Score:2)