Solid State Laser News

Forest Green said:
www.spacewar.com

New laser technology speeds up landmine detection process

Los Angeles CA (SPX) Nov 02, 2024 - Enough landmines are buried worldwide to circle the Earth twice at the equator, posing a significant challenge for identification and removal, which is both costly and time-consuming. Research
www.spacewar.com
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The technique of using a coherent Doppler laser vibrometer for detection of land mines is not new. Work was done on this going back to the late 1980s. Improvements in the acoustic exciters, lasers, sensors and data processors have made the devices more compact and able to have more beams and sensing channels in a single device to scan faster over a larger area and while on the move.

Dr. James Sabatier started that research at the University of Mississippi in the late '80s and early '90s. Dr. Vyacheslav Aranchuk, who is quoted in the article, became involved in that work sometime in the '90s, I believe. The organization that I worked for in the late '80s to late '90s, the U.S. Army Night Vision and Electronic Sensors Directorate (NVESD), funded and collaborated on some of their early work. We were doing R&D on laser vibrometry for various military applications at the time, including mine detection. There was also a group at MIT Lincoln Labs that got involved in laser vibrometry for mine detection sometime in the late '90s or early 2000s.

It is nice to see from the article what progress has been made on using laser vibrometers for the detection of land mines after all of these years since that research was started.
 
Raytheon contracted for Wireless power delivery by the US Army:

Wireless power beaming is designed to reduce logistical challenges by eliminating the need for fuel and batteries, while also enhancing operational efficiency and minimizing the exposure of troops to risk, the company says. The technology could also provide consistent energy delivery to sensor systems without relying on centralized fuel depots, which can be vulnerable to threats, the statement adds.
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militaryembedded.com

Wireless power beaming technology for U.S. Army to be developed by Raytheon - Military Embedded Systems

EL SEGUNDO, California. Raytheon won a contract from the U.S. Army to develop wireless power beaming technology for battlefield applications, the company announced in a statement.
militaryembedded.com militaryembedded.com
 
TomcatViP said:
Raytheon contracted for Wireless power delivery by the US Army:



militaryembedded.com

Wireless power beaming technology for U.S. Army to be developed by Raytheon - Military Embedded Systems

EL SEGUNDO, California. Raytheon won a contract from the U.S. Army to develop wireless power beaming technology for battlefield applications, the company announced in a statement.
militaryembedded.com militaryembedded.com
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armyrecognition.com

US Army Partners with Raytheon to Enhance Battlefield Logistics with Directed Energy

US Army Partners with Raytheon to Enhance Battlefield Logistics with Directed Energy
armyrecognition.com armyrecognition.com
 
TomcatViP said:
Raytheon contracted for Wireless power delivery by the US Army:



militaryembedded.com

Wireless power beaming technology for U.S. Army to be developed by Raytheon - Military Embedded Systems

EL SEGUNDO, California. Raytheon won a contract from the U.S. Army to develop wireless power beaming technology for battlefield applications, the company announced in a statement.
militaryembedded.com militaryembedded.com
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Is this microwave, millimeter wave or optical power beaming? I don't see it specified in the article.
 
@bcredman :
Probably MW as William Brown 1960's experiment is widely cited in the same lines.
It fits also the mention of sensor, data and isolated platoons with something like a portable Starlink antenna being used for both needs.
Laser power beaming is easier in clear line of sight, which would preclude troops from isolating and concealing themselves ;)

View: https://youtu.be/9angvpwHOy8
 
TomcatViP said:
@bcredman :
Probably MW as William Brown 1960's experiment is widely cited in the same lines.
It fits also the mention of sensor, data and isolated platoons with something like a portable Starlink antenna being used for both needs.
Laser power beaming is easier in clear line of sight, which would preclude troops from isolating and concealing themselves ;)

View: https://youtu.be/9angvpwHOy8
Click to expand...
I thought that too, for the reasons you state, but then I saw the article https://thedefensepost.com/2024/11/15/us-power-beaming-raytheon/ which states:
"Raytheon accepted a similar project in December 2023 worth $10 million to produce a wireless airborne power-generating capability for DARPA.

The award was facilitated under the tactical innovation agency’s Persistent Optical Wireless Energy Relay (POWER) program inaugurated in 2022 to address traditional energy source requirements in the military with optical wireless energy approaches."

The article at the link in that statement about the contract Raytheon received in December of 2023 says "Under the two-year contract, Raytheon will design an airborne solution producing “webs” that collect, transmit, and redirect optical beams.

These laser webs will carry energy from ground sources to high altitudes to sustain long-range and precision power distribution for sensors, effectors, and unmanned systems.

According to Raytheon, the resulting POWER energy solution will decrease the warfighters’ dependence on traditional fuel, corresponding delivery, and storage."
 
publiusr said:
lasers can cast shadows

The researchers say that from a technological perspective, the effect they demonstrated shows that the intensity of a transmitted laser beam can be controlled by applying another laser.
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They are misrepresenting what is going on when they say that light casts the shadow. It is actually the nonlinear optical medium's response to the "object" light that casts a shadow in the illumination light.

From the article "they used a ruby crystal and specific laser wavelengths to show that a laser beam could block light and create a visible shadow due to a nonlinear optical process. This effect occurs when light interacts with a material in an intensity-dependent way and can influence another optical field...To do this, the researchers directed a high-power green laser [object light] through a cube made of standard ruby crystal and illuminated it with a blue laser from the side. When the green laser enters the ruby, it locally changes the material response to the blue wavelength."

The next statement in the article "The green laser acts like an ordinary object while the blue laser acts like illumination. The interaction between the two light sources created a shadow on a screen that was visible as a dark area where the green laser blocked the blue light." is not accurately depicting what is happening. The correct statement would be "The nonlinear response of the region of the ruby crystal interacting with the green laser light acts like an opaque object to the blue laser illumination. The nonlinear interaction between the ruby crystal and the two light sources created a shadow on a screen that was visible as a dark area where the green laser illuminated region of the ruby crystal blocked the blue light."

After making the gee-whiz seemingly impossible paradoxical statements about light casting a shadow, the end of the article says what is actually happening: "The laser shadow effect is a consequence of optical nonlinear absorption in the ruby. The effect occurs because the green laser increases the optical absorption of the blue illuminating laser beam, creating a matching region in the illuminating light with lower optical intensity. The result is a darker area that appears as a shadow of the green laser beam."
 
Rather like a sunspot simulation.

I remember a weak lamp in an old classroom overhead projector deal that put a weak light in a dark room...you could see a "smear" of light on the wall.

Then a massive light was turned on from behind the weak bulb--and it looked like a shadow. The light from the weak bulb was still there...just washed out.

I have heard it said that a white piece of paper under the glow of the Moon is darker than a jet black cat at noon. Tough to envision...I think it was an editor of ASTRONOMY or Sky & 'Scope.

Still, this laser find may be useful.

Optics find
 
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publiusr said:
Rather like a sunspot simulation.

I remember a weak lamp in an old classroom overhead projector deal that put a weak light in a dark room...you could see a "smear" of light on the wall.

Then a massive light was turned on from behind the weak bulb--and it looked like a shadow. The light from the weak bulb was still there...just washed out.

I have heard it said that a white piece of paper under the glow of the Moon is darker than a jet black cat at noon. Tough to envision...I think it was an editor of ASTRONOMY or Sky & 'Scope.

Still, this laser find may be useful.
Click to expand...
This "laser find" is not a new concept. Controlling light with light using nonlinear optical materials has been around for decades and it has been very useful. See for example the 2002 IEEE article "Controlling light with light: nonlinear optics applications in optical communications" at https://ieeexplore.ieee.org/document/1034229 and the 1985 book " Optical bistability: controlling light with light" at https://www.osti.gov/biblio/5627998
 
@bcredman :
Regarding Optical Vs MW for power generation, I think you are right, and that is in line with what we have discussed in the past, but with the downlink.
I really see the last leg being better with MW than an optical link for the reasons detailed in my previous post.

I understand the graphics have image that represent an UAV being used grossly as a reflector to direct a laser toward the grounds where there is friendly troops but the details are cringing with why you would need the laser to run through the entire length of vehicle from back to front, if that was not for processing and conversion.
IMOHO, the laser link is converted to electricity that is then used to emit a signal toward the final receiver via a GAN/GaAS antennae. Optical is very good out of the last 1000ft where you have your convection layer, foliage, diffraction from dust and organic matter etc... Below that, MW is more agile.
 
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TomcatViP said:
@bcredman :
Regarding Optical Vs MW for power generation, I think you are right, and that is in line with what we have discussed in the past, but with the downlink.
I really see the last leg being better with MW than an optical link for the reasons detailed in my previous post.

I understand the graphics have image that represent an UAV being used grossly as a reflector to direct a laser toward the grounds where there is friendly troops but the details are cringing with why you would need the laser to run through the entire length of vehicle from back to front, if that was not for processing and conversion.
IMOHO, the laser link is converted to electricity that is then used to emit a signal toward the final receiver via a GAN/GaAS antennae. Optical is very good out of the last 1000ft where you have your convection layer, foliage, diffraction from dust and organic matter etc... Below that, MW is more agile.
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I agree that a hybrid optical and MW wireless power transfer system makes sense, but it is not clear if that is what Raytheon is actually doing on this contract.

Also, the Army could be letting contracts for different subsystems of the overall system development to different companies, so that one company does the MW subsystem and another company does the optical system, and a third company does the ground platforms and a fourth company does the air platforms. This is often done in early development stages, but for more mature systems, a contract would go to a prime contractor for the whole system, and the prime contractor would select its subcontractors for the subsystems and components. There's not enough detail in the articles to determine how this procurement is structured.
 
https://telegrafi.com/en/japonia-sy...rinat-hapesinore-duke-perdorur-laser-ne-toke/

Startup EX-Fusion, based in Osaka, Japan, aims to develop a laser system that will be used to destroy space debris from the Earth's surface. This innovative approach could become a valuable way to "clean up" the increasingly congested space around our planet.

EX-Fusion's method will use pulsed DPSS lasers to apply force to fast-moving debris, stopping it like a brake.

"Laser power for destroying space debris is an order of magnitude lower than that of nuclear fusion, but they share technical challenges such as steering through special mirrors," said company director Kazuki Matsuo.

EX-Fusion plans to "beam" space debris from Earth, but faces development difficulties related to accuracy and power. However, it still has the advantage that maintenance and upgrades can be done on Earth.

See also: https://thehill.com/opinion/technology/4829683-china-rocket-launch-space-debris/
 
Forest Green said:
So is the plan to slow it down so that it burns up in the atmosphere?
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Yes, and they are targeting small pieces of debris. From the article: "The initial phase of this project will involve deploying laser technology to track space debris smaller than 10 centimeters in size. This size of debris is challenging for laser targeting from Earth...The method involves firing an intermittent laser in the opposite direction of the debris to slow it down. This reduction in orbital velocity should, in theory, lead to debris entering Earth's atmosphere, where it will burn up."
 

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