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
 
lasers can cast shadows
phys.org

Scientists discover laser light can cast a shadow

Can light itself cast a shadow? It may sound like a philosophical riddle, but researchers have found that under certain conditions, a laser beam can act like an opaque object and cast a shadow. The discovery challenges the traditional understanding of shadows and opens new possibilities for...
phys.org phys.org

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.
 
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
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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
phys.org

Scientists discover laser light can cast a shadow

Can light itself cast a shadow? It may sound like a philosophical riddle, but researchers have found that under certain conditions, a laser beam can act like an opaque object and cast a shadow. The discovery challenges the traditional understanding of shadows and opens new possibilities for...
phys.org phys.org

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.
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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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View: https://m.youtube.com/watch?v=hf_zFD13T0Q
 
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publiusr said:
Space laser

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phys.org
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The laser discussed at https://phys.org/news/2024-11-team-world-tunable-wavelength-blue.html is not the world's first tunable-wavelength blue semiconductor laser. This 2019 article "Single longitudinal mode external cavity blue InGaN diode laser" presents one and discusses other previous ones: https://www.sciencedirect.com/science/article/abs/pii/S0030399218320929
 
ZVRN4HHJCBHCJDHP56WZ5E3HAA.jpg


Wolfhound%20fitted%20with%20Raytheon%20High-Energy%20Laser%20Weapon%20System%20220724%20CREDIT%20DSTL.jpg

Wolfhound mounted Land Laser Directed Energy Weapon Demonstrator program shot down dozens of quadcopter drones at a range of between 1-5km at Porton Down (the maximum length of the firing range) with a 100% engagement success rate.

www.defensenews.com

British troops test laser weapon as cheap option to fry drones

The British Army’s experimental laser weapon uses advanced sensors and tracking systems to maintain lock on target.
www.defensenews.com www.defensenews.com
 
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https://twitter.com/x/status/1868699480108970260

We can state that today Ukraine is, if I'm not mistaken, the fifth country that can say that it has a laser. Today, we can already shoot down planes with this laser at an altitude of over 2 km," he said during an address to participants of the conference "European Defense Industry: Prospects for Cooperation with the Ukrainian Defense Industry", organized by the We Build Ukraine think tank.
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Forest Green said:
Yes, I spotted that straight away. There was talk of the DragonFire going to Ukraine for testing, so I was actually wondering about that.
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IMHO more probable that they jury-rigged - it's not a denigrating term here - some focusing & tracking system to commercial kilowatt-grade laser (for example, laser welder).
 
Dilandu said:
IMHO more probable that they jury-rigged - it's not a denigrating term here - some focusing & tracking system to commercial kilowatt-grade laser (for example, laser welder).
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This BBC News article from April 2024, https://www.bbc.com/news/uk-68795603 , states:

"A UK high-power laser weapon could be sent to Ukraine to take down Russian drones, the defence secretary says.

According to Grant Shapps, the weapon could have "huge ramifications" for the conflict in Europe.

The DragonFire weapon is expected to be rolled out by 2027, but Mr Shapps said he wanted to "speed up" production and make it available sooner...

"Let's say that it didn't have to be 100% perfect in order for Ukrainians perhaps to get their hands on it," he said.

The Ministry of Defence (MoD) says the faster timetable comes in response to the "rapidly changing threat environment" faced by the UK.

"It's designed to not wait until we have this at 99.9% perfection before it goes into the field, but get it to sort of 70% and then get it out there and then develop it from there," Mr Shapps said.

"But 2027 is still the date as of this moment," he continued."

This October 2024 article, https://armyrecognition.com/focus-a...fire-laser-weapon-systems-from-united-kingdom , states:

"On 11 October 2024, Ukrainian Defense Minister Rustem Umerov announced that he discussed the provision of the British DragonFire laser weapon with his British counterpart, John Healey, during his visit to London. “We talked about DragonFire. We are actively working on this project,” Umerov said during a televised marathon."
 
TomcatViP said:
But no plasma on plastics.
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Please clarify your statement.

Are you saying that no plasma forms on plastics in laser ablation of plastics?

If so, that statement is not true in general. See https://www.sciencedirect.com/science/article/pii/S2351978919308832 p. 320 which states:

"Polyimide is a high temperature engineering plastic. Polyimides are thermally stable even up to the temperature range of 300-400 ˚C. As a result of its high heat and fire resistance compared to other polymer materials, PI is suitable for a diverse range of applications such as aerospace, optoelectronics, and defense...Research has been conducted to determine the influence of laser parameters such as pulse duration and pulse repetition rate on the ablation of polyimides...It was concluded that the trailing part of the laser pulse was blocked by the plasma plume and the excited polymer particles, which prevented the laser from hitting the polymer substrate."
 
jsport said:
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The Popular Mechanics article "The Secret History of Plasma Weapons - After decades of promise and failure, a new plasma weapon emerges" By David Hambling, Updated: May 23, 2022 1:05 PM EDT available at
https://www.popularmechanics.com/military/research/a25091957/plasma-weapon-history/ has some interesting historical information on laser plasma weapons from PIKL to SCUPLS (Scalable Compact Ultra-Short Pulse Laser System).

"In September 2018, the JNLWD began a three-year project to finally produce a viable nonlethal laser plasma weapon. The latest addition to the alphabet soup of laser weapon names is SCUPLS, for Scalable Compact Ultra-Short Pulse Laser System, and it will use new short-pulse lasers.

SCUPLS has a triple function, recalling some of the earlier projects: conveying spoken messages at long range, producing deafening flash-bangs either in the air or on a target, and “thermal ablation for pain.” At low power levels it will be able to produce thousands of detonations a second like PASS...

'We need better lasers with approximately another order of magnitude increase in power per pulse,' says David Law, chief scientist of the Pentagon’s JNLWD. 'A next-generation family of ultra-short pulse lasers will be required to enable the fully non-lethal capability at range.'"
 
@bcredman : forgot Pa6 was Nylon. I stand corrected.

SCULPS and alike however are the open door for every man portable gas chamber. It's an horrible weapon that should only be strictly controlled, with every usage restricted, every items accounted and civilian be offered to buy detectors instead of being arbitrarily prevented of any means of defense (detection, recording and tracking) by bandwidth legal restriction.
 
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TomcatViP said:
@bcredman : forgot Pa6 was Nylon. I stand corrected.

SCULPS and alike however are the open door for every man portable gas chamber. It's an horrible weapon that should only be strictly controlled, with every usage restricted, every items accounted and civilian be offered to buy detectors instead of being arbitrarily prevented of any means of defense (detection, recording and tracking) by bandwidth legal restriction.
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every man portable gas chamber.
Always enjoy your posts, but could you elaborate on the above please TomcatVIP ?
 
I have already shared how DEW allows intrusive and undetectable persecution of the many by a few. In essence, it's a WMD that doesn't say it's name. It should be regulated on the most stringent manner.
It's intrinsic attributes made it an instrument of choice for a dark cohorte of people building upon an history of social violence and mass abuse. We have already long passed the point where those are the only subjects of what if scenario or elaborated Spy stories.
 
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TomcatViP said:
@bcredman : forgot Pa6 was Nylon. I stand corrected.

SCULPS and alike however are the open door for every man portable gas chamber. It's an horrible weapon that should only be strictly controlled, with every usage restricted, every items accounted and civilian be offered to buy detectors instead of being arbitrarily prevented of any means of defense (detection, recording and tracking) by bandwidth legal restriction.
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In an earlier version of your post you stated "Polyamides are not the plastic material commonly used in UAS (Polypropylene and Polycarbonates)."

Just for the record, I wanted to provide the following references indicating that plasmas do form during laser ablation of Polypropylene and Polycarbonates.

https://www.sciencedirect.com/science/article/pii/S0169433211018812 "Effect of pulse repetition rate and number of pulses in the analysis of polypropylene and high density polyethylene by nanosecond infrared laser induced breakdown spectroscopy" excerpts:

"LIBS has been established as an important analytical tool which allows direct analysis of solids without or with minimum sample preparation. This technique uses laser ablation for sampling and subsequent measurement of the emission intensity of UV–visible radiation from excited atoms and/or ions in laser-induced microplasma [1,2]...

In this work, the effects of pulse repetition rate and number of pulses on the topographical features of the craters in LIBS analysis of high density polyethylene (HDPE) and polypropylene (PP) were studied by scanning electron microscopy (SEM) and perfilometry."

Note that if no laser-induced plasma were created by laser ablation of polypropylene and high density polyethylene, then LIBS could not be used on these plastics.


https://etd.auburn.edu/bitstream/handle/10415/2467/dissertation.pdf?sequence=3&isAllowed=y "Investigations of Laser Ablation and Laser-Induced-Plasma Ignition of Cyclotrimethylenetrinitramine (RDX)" excerpt:

"Since the first reports on laser ablation of polymers in 1982, [73],[74] there are numbers of review articles in this subject that have been published. [75] , [76] , [77] , [78] A polymer is a large molecule, consisting of repeating smaller molecular units (monomer) with basic elements as carbon, hydrogen, oxygen and sometimes also nitrogen. The commonly studied polymers which are also commercially available, include polyimide (PI), polymethylmethacrylate (PMMA), and polycarbonate (PC). A new type of designed triazene polymer (TP) has also been intensively studied...

The main implementation of plasma initiation is in Electrothermal-Chemical (ETC) guns, where an electrical pulse is passed through a chemical material to generate a high-energy density plasma, inducing the ignition of energetic materials...

A laser-induced-plasma interaction with propellant, which will be introduced in later chapter, was designed as a new experimental modeling of PPI process. This model bears the following promising features: (1) by using same plasma generating materials as used in ETC system, such as polycarbonate, a laser-induced-plasma will resemble the plasma generated from an ETC pulse; (2) highly tunable parameters with a laser pulse indicates a possible precise control of the generated plasma, optimizing propellant performance; (3) replacement of a bulky capacitor as power supply in a traditional ETC system with a laser, which is the size of a computer case...

A laser-induced-plasma initiation has been proposed and investigated in the fourth chapter. In this design, a polymer material as used in ETC, in this case polycarbonate, is the source material to be converted into localized plasma by a UV-laser pulse. This plasma, which resembles the one generated from ETC pulse in many ways, as discussed in section 1.2.5, is expected to initiate the main charge. In addition, laser ablation of polymers has been discussed in terms of mechanisms and plasma plume formation...

Chapter 4 presents a preliminary investigation on laser-induced-plasma initiation of RDX. A thin polycarbonate (PC) film has been used as the plasma generating source. A sample of PC film spin-coated on top of RDX has been exposed to laser pulse irradiation. The laser–induced plasma initiation has been probed and proved through a variety of approaches, namely, gas products pressure detection, observation of reflected light, witness board experiment and dynamic pressure measurement. All approaches provided evidence for an initiation of RDX films by a laser-induced-plasma."
 
TomcatViP said:
@bcredman : forgot Pa6 was Nylon. I stand corrected.

SCULPS and alike however are the open door for every man portable gas chamber. It's an horrible weapon that should only be strictly controlled, with every usage restricted, every items accounted and civilian be offered to buy detectors instead of being arbitrarily prevented of any means of defense (detection, recording and tracking) by bandwidth legal restriction.
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The acronym is SCUPLS rather than SCULPS.

SCUPLS stands for Scalable Compact Ultra-short Pulse Laser System.
 
jsport said:
www.defensenews.com

France tests space lasers for secure satellite downlink in world first

The point-to-point nature of lasers makes them more secure than radio frequencies, and they can’t be jammed the way radio can.
www.defensenews.com www.defensenews.com
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Forest Green posted the above article link previously on 13 September 2024, to which I responded as follows:

bcredman said:
The article states "While the experiment is not the first for space-to-Earth laser communications, it’s the first using a commercially available ground station, according to Morizur."

NASA's 2017 Optical Communications and Sensor Demonstration (OCSD) conducted the first-ever high-speed laser communications downlink from a CubeSat to a ground station, as well as demonstrating an optical communications uplink to a CubeSat for the first time.

The abstract to a 12 July 2019 Aerospace Corporation presentation on OCSD https://digitalcommons.usu.edu/cgi/viewcontent.cgi?article=4298&context=smallsat states: "In this presentation, we discuss the first demonstration of a lasercom downlink from a LEO 1.5U 2.3 kg CubeSat to our optical ground station at The Aerospace Corporation in El Segundo, CA."

I'm not sure of Morizur's definition of "a commercially available ground station," but The Aerospace Corporation is a commercial company.
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