Solid State Laser News

[indicisivedivide]

No talk about diode pumped rare gas and alkali lasers.

 

[indicisivedivide]

XeF lasers have a typical wall-plug efficiency of only 0.2% which is far lower than the wall-plug efficiency of the NIF tripled Nd:glass laser system which is 0.66% for the flash lamp pumped version and 5% for the diode pumped version as shown in the table below from https://www.osti.gov/servlets/purl/951674 (Note that LIFE is a proposed fusion-fission-hybrid energy generation engine based on laser-driven ICF and the efficiencies in the LIFE column are calculated rather than actually achieved efficiencies as are the values in the two NIF columns):

View attachment 701414

Odd, I have a book that states efficiencies of up to 15% had been demonstrated with excimer lasers, and it was written in the late '80s.

Now they're stating up to 5% but more with electron beam pumping.

excimer lasers

Excimer lasers are lasers where optical amplification occurs in a plasma containing excited dimers with an anti-binding electronic ground state.

www.rp-photonics.com

Beam pumped.
From 1988

Increased XeF(B→X) laser efficiency at high pump rate and elevated temperature

A XeF(B→X) laser efficiency of 6.0% has been observed in an electron beam pumped device. This is the highest XeF(B→X) laser efficiency reported to date. Mixture

pubs.aip.org

Efficient narrowband electron beam pumped KrF laser for pulse‐compression studies

A 25‐J, 50‐ns laser pumped by opposed electron beams is described. Experiments with this device demonstrated a 9% intrinsic laser efficiency at power deposition

pubs.aip.org

Direct drive with the argon fluoride laser as a path to high fusion gain with sub-megajoule laser energy - PMC

Argon fluoride (ArF) is currently the shortest wavelength laser that can credibly scale to the energy and power required for high gain inertial fusion. ArF's deep ultraviolet light and capability to provide much wider bandwidth than other ...

www.ncbi.nlm.nih.gov

LIFE used a solid-state laser known as the Mercury laser, using Yb:SFAP (Ytterbium-doped strontium fluorapatite, Sr5(PO4)3F) as the active gain medium.

Mercury laser - Wikipedia

en.wikipedia.org

I had seen 5% for KrF, but only 0.2% for XeF, so those numbers cover the range in the RP Photonics article. The XeF number was for an electrical discharge pumped XeF laser and came from a very old reference (1976): https://pubs.aip.org/aip/apl/articl...charge-initiated-XeF-laser?redirectedFrom=PDF

Also, some of the larger stated efficiencies may not be wall-plug efficiencies. For example, your link about narrowband electron beam pumped KrF laser for pulse‐compression studies, lists a 9% intrinsic laser efficiency, but that is not a wall-plug efficiency. For electron beam pumped excimer lasers, the intrinsic laser efficiency is defined as the ratio of the laser output energy to the e-beam energy deposited into the laser gas. See https://opg.optica.org/directpdfacc...&id=299350&uri=CLEO-1988-TUO4&seq=0&mobile=no

The link about the ArF laser for direct drive fusion is about ArF, not XeF, and the numbers are projected efficiencies, not achieved efficiencies as indicated in this excerpt "Our laser kinetics simulations indicate that the electron beam-pumped ArF laser can have intrinsic efficiencies of more than 16%, versus about 12% for the next most efficient krypton fluoride excimer laser. We expect at least 10% ‘wall plug' efficiency for delivering ArF light to target should be achievable using solid-state pulsed power and efficient electron beam transport to the laser gas that was demonstrated with the U.S. Naval Research Laboratory's Electra facility."

The 5% wall plug efficiency you stated is on par with the 5% demonstrated by the tripled diode laser pumped Nd:glass laser demonstrated in NIF.

The 15% wall plug efficiency you stated is not significantly different from the 13.3% expected for the LIFE laser, but in both cases these seem to be calculated projections rather than demonstrated wall plug efficiencies.

Consistently throughout my 40-year career in lasers and electro-optics, I saw projected laser efficiencies for new laser technologies that were significantly higher than what was achieved, sometimes by as much as factors of 2 or 3. So, I take the projected efficiencies with a grain of salt.

About LIFE: "LIFE, short for Laser Inertial Fusion Energy, was a fusion energy effort run at Lawrence Livermore National Laboratory between 2008 and 2013...Two designs were considered, operated as either a pure fusion or hybrid fusion-fission system....With the problem of ignition unsolved, the LIFE project was canceled in 2013...The LIFE program was criticized through its development for being based on physics that had not yet been demonstrated. In one pointed assessment, Robert McCrory, director of the Laboratory for Laser Energetics, stated: "In my opinion, the overpromising and overselling of LIFE did a disservice to Lawrence Livermore Laboratory."...LLNL had begun exploring different solutions to the laser problem while the system was first being described. In 1996 they built a small testbed system known as the Mercury laser that replaced the flashtubes with laser diodes." From https://en.wikipedia.org/wiki/Laser_Inertial_Fusion_Energy

The LIFE laser listed in the table I excerpted from the LLNL report was for the hybrid fusion-fission concept, and it's performance listed in the table was a projection, not what was achieved.

KrF and ArF are DUV lasers. So they can't be used in the open. They need pure air ( clean room air ) to function.

 

[Forest Green]

KrF and ArF are DUV lasers. So they can't be used in the open. They need pure air ( clean room air ) to function.

Wavelengths just below visible are still inside the atmospheric window and typical metals have much lower reflectance below 400nm.

 

[bcredman]

No talk about diode pumped rare gas and alkali lasers.

I don't know much about them, but there are interesting papers about them at these links:
https://opg.optica.org/oe/fulltext.cfm?uri=oe-23-11-13823&id=318852 and
https://apps.dtic.mil/sti/pdfs/AD1097889.pdf

Perhaps someone more knowledgeable will chime in on these types of lasers and their potential for defense and aerospace applications.

 

[bcredman]

XeF lasers have a typical wall-plug efficiency of only 0.2% which is far lower than the wall-plug efficiency of the NIF tripled Nd:glass laser system which is 0.66% for the flash lamp pumped version and 5% for the diode pumped version as shown in the table below from https://www.osti.gov/servlets/purl/951674 (Note that LIFE is a proposed fusion-fission-hybrid energy generation engine based on laser-driven ICF and the efficiencies in the LIFE column are calculated rather than actually achieved efficiencies as are the values in the two NIF columns):

View attachment 701414

Odd, I have a book that states efficiencies of up to 15% had been demonstrated with excimer lasers, and it was written in the late '80s.

Now they're stating up to 5% but more with electron beam pumping.

excimer lasers

Excimer lasers are lasers where optical amplification occurs in a plasma containing excited dimers with an anti-binding electronic ground state.

www.rp-photonics.com

Beam pumped.
From 1988

Increased XeF(B→X) laser efficiency at high pump rate and elevated temperature

A XeF(B→X) laser efficiency of 6.0% has been observed in an electron beam pumped device. This is the highest XeF(B→X) laser efficiency reported to date. Mixture

pubs.aip.org

Efficient narrowband electron beam pumped KrF laser for pulse‐compression studies

A 25‐J, 50‐ns laser pumped by opposed electron beams is described. Experiments with this device demonstrated a 9% intrinsic laser efficiency at power deposition

pubs.aip.org

Direct drive with the argon fluoride laser as a path to high fusion gain with sub-megajoule laser energy - PMC

Argon fluoride (ArF) is currently the shortest wavelength laser that can credibly scale to the energy and power required for high gain inertial fusion. ArF's deep ultraviolet light and capability to provide much wider bandwidth than other ...

www.ncbi.nlm.nih.gov

LIFE used a solid-state laser known as the Mercury laser, using Yb:SFAP (Ytterbium-doped strontium fluorapatite, Sr5(PO4)3F) as the active gain medium.

Mercury laser - Wikipedia

en.wikipedia.org

I had seen 5% for KrF, but only 0.2% for XeF, so those numbers cover the range in the RP Photonics article. The XeF number was for an electrical discharge pumped XeF laser and came from a very old reference (1976): https://pubs.aip.org/aip/apl/articl...charge-initiated-XeF-laser?redirectedFrom=PDF

Also, some of the larger stated efficiencies may not be wall-plug efficiencies. For example, your link about narrowband electron beam pumped KrF laser for pulse‐compression studies, lists a 9% intrinsic laser efficiency, but that is not a wall-plug efficiency. For electron beam pumped excimer lasers, the intrinsic laser efficiency is defined as the ratio of the laser output energy to the e-beam energy deposited into the laser gas. See https://opg.optica.org/directpdfacc...&id=299350&uri=CLEO-1988-TUO4&seq=0&mobile=no

The link about the ArF laser for direct drive fusion is about ArF, not XeF, and the numbers are projected efficiencies, not achieved efficiencies as indicated in this excerpt "Our laser kinetics simulations indicate that the electron beam-pumped ArF laser can have intrinsic efficiencies of more than 16%, versus about 12% for the next most efficient krypton fluoride excimer laser. We expect at least 10% ‘wall plug' efficiency for delivering ArF light to target should be achievable using solid-state pulsed power and efficient electron beam transport to the laser gas that was demonstrated with the U.S. Naval Research Laboratory's Electra facility."

The 5% wall plug efficiency you stated is on par with the 5% demonstrated by the tripled diode laser pumped Nd:glass laser demonstrated in NIF.

The 15% wall plug efficiency you stated is not significantly different from the 13.3% expected for the LIFE laser, but in both cases these seem to be calculated projections rather than demonstrated wall plug efficiencies.

Consistently throughout my 40-year career in lasers and electro-optics, I saw projected laser efficiencies for new laser technologies that were significantly higher than what was achieved, sometimes by as much as factors of 2 or 3. So, I take the projected efficiencies with a grain of salt.

About LIFE: "LIFE, short for Laser Inertial Fusion Energy, was a fusion energy effort run at Lawrence Livermore National Laboratory between 2008 and 2013...Two designs were considered, operated as either a pure fusion or hybrid fusion-fission system....With the problem of ignition unsolved, the LIFE project was canceled in 2013...The LIFE program was criticized through its development for being based on physics that had not yet been demonstrated. In one pointed assessment, Robert McCrory, director of the Laboratory for Laser Energetics, stated: "In my opinion, the overpromising and overselling of LIFE did a disservice to Lawrence Livermore Laboratory."...LLNL had begun exploring different solutions to the laser problem while the system was first being described. In 1996 they built a small testbed system known as the Mercury laser that replaced the flashtubes with laser diodes." From https://en.wikipedia.org/wiki/Laser_Inertial_Fusion_Energy

The LIFE laser listed in the table I excerpted from the LLNL report was for the hybrid fusion-fission concept, and it's performance listed in the table was a projection, not what was achieved.

KrF and ArF are DUV lasers. So they can't be used in the open. They need pure air ( clean room air ) to function.

The discussion on the excimer lasers started with XeF at 351 nm, which has passable, but not great, atmospheric transmittance. But then the discussion wandered off to ArF, which has a wavelength of 193 nm, and KrF, which has a wavelength of 248 nm. Both of those wavelengths have much worse atmospheric transmittance. ArF and KrF entered the discussion because there were some references on various pumping schemes for them to improve the efficiency, which may or may not be applicable to XeF.

 

[bcredman]

Raytheon delivers mobile 10kW laser weapon to US Air Force...​

13 Jun 2023

...as Airforce Research Lab completes flight tests for directed energy laser system beam director.

Raytheon delivers mobile 10kW laser weapon to US Air Force...

...as Airforce Research Lab completes flight tests for directed energy laser system beam director.

optics.org

"In the fall of 2022, the U.S. Air Force Life Cycle Management Center and Raytheon Technologies reported the successful testing of the Air Force’s first palletized high-energy laser weapon during four days of continuous live-fire exercises at White Sands Missile Range in New Mexico.

The new palletized laser weapon was the first 10-kilowatt laser built to U.S. military specifications in a stand-alone configuration that can be moved and mounted where needed. Known as H4, this is the fourth operational laser weapon system that Raytheon has delivered to the USAF and the eighth total system the company has delivered to the Department of Defense.

The laser weapon, designed to protect people and assets against short-range aerial threats, passed the USAF’s Test and Assessment plan. This included multiple days of live-fire exercises to acquire, target, track and destroy drone targets in short-range attack, swarm attack, and long-range threat scenarios.

“Anywhere the Air Force sees a threat from drones, they now have four proven laser weapons that can be deployed to stop asymmetrical threats,” commented Michael Hofle, senior director of High-Energy Lasers at Raytheon Technologies. “Whether at a fixed location, a flatbed truck or even a pickup, these laser weapons are compact, rugged and ready to go.”
...

AFRL completes flight tests for directed energy laser system beam director

The US Air Force Research Laboratory has completed a successful flight-test campaign for a new beam director concept that can be used with directed energy laser systems integrated onto aircraft.

The Hybrid Aero-Effect Reducing Design with Realistic Optical Components, or HARDROC, team, consisting of personnel from AFRL’s Aerospace Systems Directorate here and Directed Energy Directorate at Kirtland AFB, New Mexico, along with prime contractor MZA Associates, has developed and tested a low-power, sub-scale beam director to evaluate the ability of various aerodynamic flow control techniques to mitigate optical and mechanical distortions imparted on a laser beam leaving an airborne platform travelling at high speeds."

 

[Forest Green]

So, Ytterbium Lasers Very efficient, but how good is it at MW power level?

Photonic Frontiers: High-efficiency Optical Pumping: 'Going green' cranks up the laser power

Improving optical-pumping efficiency has made solid-state lasers cost-effective industrial tools. Continuing refinements will improve laser performance by reducing nonlinear effects...

www.laserfocusworld.com

 

[bcredman]

So, Ytterbium Lasers Very efficient, but how good is it at MW power level?

Photonic Frontiers: High-efficiency Optical Pumping: 'Going green' cranks up the laser power

Improving optical-pumping efficiency has made solid-state lasers cost-effective industrial tools. Continuing refinements will improve laser performance by reducing nonlinear effects...

www.laserfocusworld.com

Northrop Grumman says they think they can scale ytterbium fiber lasers to MW using coherent beam combining. The article at this link https://www.photonics.com/Articles/Fiber_Lasers_Scale_Up_Output_Powers_and_End/a68982 states: "Defense specialist Northrop Grumman has guided the way for building some of the highest power fiber lasers for countering threats including unmanned aerial systems, rockets, artillery, and mortar shells. The company is also currently developing its highest energy laser yet, which will be able to scale output up to 1 MW...

Northrop Grumman’s Laser Weapon System Demonstrator recently completed deployment of the U.S. Navy’s USS Portland. The 150-kW class laser system tracks targets and employs directed energy to stop and destroy hostile drones, small craft, and other threats. It is reportedly the most powerful electric high-energy laser system ever deployed on a U.S. Navy ship.

To extend the defense applications of fiber lasers, it is important for these sources to attain higher system power to defeat more difficult threats, such as cruise and hypersonic missiles at longer ranges. One way that Northrop Grumman achieves this is by focusing on advancing fiber laser amplifiers, particularly on combining the beams from multiple amplifiers.

Scaling fiber laser power involves combining the outputs of multiple fiber amplifiers into a single beam. “This can be done in several ways,” Keller said. “Many higher power lasers built in the last decade have used spectral beam combining. More recently, coherent beam combining has emerged as a technical path to build megawatt-class fiber lasers.”"

See also https://www.mdpi.com/2304-6732/8/12/566

The Lockheed Martin high power laser weapons that they have been delivering over the past several years, starting at 30 kW, then going to 60 kW, and now at 300 kW, have been based on spectral beam combining of the outputs of multiple ytterbium doped fibers lasers. I don't know what the limit is for scaling them to even higher power with that technique.

See https://spectrum.ieee.org/fiber-lasers-mean-ray-guns-are-coming (from 2018) and https://interestingengineering.com/innovation/how-high-powered-lasers-work (from 2022) and https://www.nationaldefensemagazine...artin-delivers-high-powered-laser-tech-to-dod (from 2022)

The latter link states " The 300 kilowatt-class laser was developed as part of the High Energy Laser Scaling Initiative, or HELSI, which is managed by the office of the undersecretary of defense for research and engineering.

The office selected Lockheed Martin to develop the 300 kW-class capability in 2019. The company has delivered the laser — the most powerful it has ever developed — ahead of schedule, according to a Lockheed Martin press release...

The laser utilizes a “spectral beam combination architecture,” Lockheed Martin vice president of advanced product solutions Rick Cordaro said during the roundtable."

General Atomics and Boeing are taking a different approach to get to 300 kW, using a series of slab amplifiers instead of fibers: https://newatlas.com/military/ga-boeing-distributed-gain-high-energy-laser-weapon/ . Will that approach scale to MW? I don't know.

 

[Forest Green]

They reckon diode pumped alkali lasers might scale to higher power levels despite being slightly less efficient, because of better cooling.

I think current efficiencies are 50% optical to optical and diodes are around 80%, so ~40%(?) overall.

I don't know much about them, but there are interesting papers about them at these links:
https://opg.optica.org/oe/fulltext.cfm?uri=oe-23-11-13823&id=318852 and
https://apps.dtic.mil/sti/pdfs/AD1097889.pdf

Perhaps someone more knowledgeable will chime in on these types of lasers and their potential for defense and aerospace applications.

How is quantum efficiency defined (first link)?

I have found the answer. Sounds like it's another way of saying optical to optical efficiency.

quantum efficiency

A quantum efficiency is the percentage of input photons which contribute to a desired effect -- for example, light detection in a photodetector.

www.rp-photonics.com

The quantum efficiency (or quantum yield) is often of interest for processes which convert light in some way. It is defined as the percentage of the input photons which contribute to the desired effect.

So in your first link metastable Xe* has a quantum efficiency of 98%. Diode lasers to pump them can be up to 80% efficient, so that has huge potential.

What are diode lasers and where do we use them?

Learn what diode lasers are, what they are used for and when not to use them.

www.gentec-eo.com

 

[bcredman]

They reckon diode pumped alkali lasers might scale to higher power levels despite being slightly less efficient, because of better cooling.

I think current efficiencies are 50% optical to optical and diodes are around 80%, so ~40%(?) overall.

I don't know much about them, but there are interesting papers about them at these links:
https://opg.optica.org/oe/fulltext.cfm?uri=oe-23-11-13823&id=318852 and
https://apps.dtic.mil/sti/pdfs/AD1097889.pdf

Perhaps someone more knowledgeable will chime in on these types of lasers and their potential for defense and aerospace applications.

How is quantum efficiency defined (first link)?

I have found the answer. Sounds like it's another way of saying optical to optical efficiency.

quantum efficiency

A quantum efficiency is the percentage of input photons which contribute to a desired effect -- for example, light detection in a photodetector.

www.rp-photonics.com

The quantum efficiency (or quantum yield) is often of interest for processes which convert light in some way. It is defined as the percentage of the input photons which contribute to the desired effect.

So in your first link metastable Xe* has a quantum efficiency of 98%. Diode lasers to pump them can be up to 80% efficient, so that has huge potential.

What are diode lasers and where do we use them?

Learn what diode lasers are, what they are used for and when not to use them.

www.gentec-eo.com

However, you have to take into account the quantum defect between the pump photons and the laser photons: https://www.rp-photonics.com/quantum_defect.html

"In most lasers, the laser wavelength is longer than the pump wavelength (exception: upconversion lasers). This means that the energy of the laser photons is smaller than that of the pump photons – there is a so-called Stokes shift. As a consequence, the power efficiency of the laser could not be 100% even if every pump photon could be converted into a laser photon...it sets a lower limit to the loss in the conversion from pump power to laser power, i.e. an upper limit to the power efficiency...Some laser crystals (e.g. those doped with ytterbium) have a particularly small quantum defect of only a few percent of the pump photon energy, leading to potentially very high power efficiency."

You need to multiply the quantum efficiency by (1 minus the quantum defect specified as a fraction of the pump photon energy), to get the optical-to-optical power conversion efficiency.

The link above has a calculator for quantum defect. The closer the pump wavelength is to the laser wavelength, the lower the quantum defect. So, for example, a Nd:YAG laser pumped at 808 nm and outputting 1064 nm laser light, the quantum defect is 0.24. Whereas, for an Ytterbium laser pumped at 976 nm and outputting 1075 nm laser light, the quantum defect is 0.0921.

(Note: from https://www.globalsecurity.org/military/world/dew.htm "Fortuitously the fiber laser wavelength, l = 1.075 µm, is near a narrow water vapor transmission window centered at l = 1.045µm."; from https://www.coherent.com/resources/...-requirements-for-high-power-fiber-lasers.pdf "Pumping at 976nm has two distinct advantages over other pump wavelengths. Due to the lower quantum defect than at shorter wavelengths, higher efficiencies may be obtained by pumping at 976nm. More significantly, shorter fiber lengths are used, key to limiting deleterious non-linear effects. The main drawback to pumping this narrow absorption peak is the tight wavelength tolerance placed upon pump diodes."

The link https://apps.dtic.mil/sti/tr/pdf/AD1026398.pdf gives a pump wavelength of 882.2 nm for a Xe* laser emitting at 980.2 nm, for which the quantum defect is 0.1, slightly higher than the quantum defect for the Yb-doped fiber laser example of 0.0921 given above.

This link https://apps.dtic.mil/sti/tr/pdf/AD1026398.pdf , table 1, gives a Xe* laser example with 882.183 nm pump wavelength and 904.793 emission wavelength, which yields a quantum defect of 0.025, which is much lower than the quantum defect for the Yb-doped fiber laser example of 0.0921 given above.

This illustrates that the specific pump and laser wavelengths of the device have a large impact on the quantum defect, and not all laser devices of the same general type will have the same quantum defect.

 

[Forest Green]

Pump wavelength for Xe* is 904.5nm here, with output of 979.9nm, which gives 7.69% quantum defect.

https://opg.optica.org/abstract.cfm?uri=oe-27-24-36011

 

[bcredman]

Pump wavelength for Xe* is 904.5nm here, with output of 979.9nm, which gives 7.69% quantum defect.

OPG | PDF no longer available

opg.optica.org

This further corroborates the statement in my previous post "This illustrates that the specific pump and laser wavelengths of the device have a large impact on the quantum defect, and not all laser devices of the same general type will have the same quantum defect."

 

[Forest Green]

How easy is it to produce the metastable state for the rare gas lasers?

 

[bcredman]

How easy is it to produce the metastable state for the rare gas lasers?

According to https://apps.dtic.mil/sti/pdfs/AD1097889.pdf : "Rare-gas atoms promoted to metastable electronically excited states have spectroscopic properties that are closely similar to those of the alkali metals. They are readily generated using low-power electrical discharges."

 

[TomcatViP]

CILAS designed HELMA-P 2kW laser tested at sea (against micro UAV) :

https://twitter.com/x/status/1671057913098686464

View: https://twitter.com/MarineNationale/status/1671057913098686464?ref_src=twsrc%5Etfw%7Ctwcamp%5Etweetembed%7Ctwterm%5E1671057913098686464%7Ctwgr%5Eb6f0878e13488934476ad78aa3f77378c07e6016%7Ctwcon%5Es1_&ref_url=https%3A%2F%2Fwww.opex360.com%2F2023%2F06%2F20%2Fune-arme-laser-a-ete-testee-avec-succes-a-bord-de-la-fregate-de-defense-aerienne-forbin%2F

French Navy tests HELMA-P Laser Weapon from Horizon Destroyer - Naval News

The HELMA-P laser weapon system was successfully tested aboard French Navy Horizon type Air Defense destroyer Forbin.

www.navalnews.com

 

[bobbymike]

Ultrafast beam-steering breakthrough at Sandia Labs

ALBUQUERQUE, N.M. — In a major breakthrough in the fields of nanophotonics and ultrafast optics, a Sandia National Laboratories research team has demonstrated the ability to dynamically steer ligh

newsreleases.sandia.gov

 

[bcredman]

https://optics.org/news/14/6/29

European Defence Agency claims success with laser weapon project
20 Jun 2023

Pan-European 'TALOS' effort focused on novel wavelength and coherent combining of high-power sources.

Excerpts from the article:

The European Defence Agency (EDA) says its “TALOS” project to develop optical technology for future laser weapons has come to a successful conclusion, with two novel demonstrators.

Short for Tactical Advanced Laser Optical System, TALOS began in September 2019 with the aim of delivering a compact laser with the ability to quickly and precisely neutralize an agile target such as a mortar or drone, while significantly minimizing collateral damage...

At the outset of the project, single high-power lasers were limited to an output of around 30 kW, with a perceived risk of dependency on non-EU suppliers.

“The technologies to be demonstrated include elements of the high-power laser source, atmospheric turbulence compensation and precision target tracking and laser pointing systems,” stated the project brief.

Now, says EDA, those objectives have been met. “The main results obtained addressed the following areas: Concept of Operations (CONOPS), target vulnerability, laser developments at 2 µm, laser combining technology, ethics and safety, [and a] roadmap for European Laser Directed Energy Weapon (LDEW) systems,” the organization announced.

“The project implementation culminated in the development of two demonstrators: a high-power amplifier at [an] eye-safer wavelength and an innovative propagation demonstrator allowing highly efficient coherent combining on target.”

EDA claims that the results will contribute significantly to enhancing the defense capabilities of the European Union’s member states with critical laser effector technologies at an output power in excess of 100 kW.

UK sovereign effort
Project collaborators QinetiQ, Leonardo, and MBDA are also involved in the UK’s “Dragonfire” effort to produce a sovereign laser weapon capability.

Last year, MBDA said that consortium had successfully carried out the first static firing of a 50 kW laser based around QinetiQ’s phase-combined approach, focused using Leonardo’s beam director, and delivered via MBDA’s advanced image processing and command and control system.

 

[publiusr]

Of interest

A photonic-crystal surface-emitting laser built bright enough for industrial-scale cutting

A team of photonics and electronic engineers at Kyoto University has found a way to overcome the shortcomings of photonic-crystal surface-emitting lasers (PCSELs) that have prevented their use in industrial-scale cutting applications. In their study reported in the journal Nature, the group made...

phys.org

 

[Forest Green]

https://twitter.com/x/status/1678050918787604481

View: https://twitter.com/AirPowerNEW1/status/1678050918787604481?s=20

https://twitter.com/x/status/1678048589774475266

View: https://twitter.com/AirPowerNEW1/status/1678048589774475266?s=20

 

[aonestudio]

Lockheed secures $221M Army deal for high-powered air defense laser prototype - Breaking Defense

For now, the company has received more than $150 million to produce the service’s Indirect Fire Protection Capability-High Energy Laser (IFPC-HEL) prototype weapon system.

breakingdefense.com

 

[Forest Green]

https://twitter.com/x/status/1683828602952101890

View: https://twitter.com/AirPowerNEW1/status/1683828602952101890?s=20

 

[bobbymike]

Northrop Grumman Space Systems talks high-energy lasers​

Northrop Grumman Space Systems talks high-energy lasers

In this Q&A, Northrop Grumman Space Systems answers our questions about the evolution of high-energy lasers.

www.laserfocusworld.com

 

[Forest Green]

Lockheed Martin's laser power reaches new heights: Introduces 500 kW-class System

Los Angeles CA (SPX) Jul 30, 2023 - Lockheed Martin, the American aerospace titan, is breaking its power records in laser technology by escalating to a groundbreaking 500-kilowatt (kW) class laser. This development outstrips its previ

www.spacewar.com

 

[publiusr]

Laser news

Researchers show how to increase X-ray laser brightness and power using a crystal cavity and diamond mirrors

At particle accelerator facilities around the world, scientists rely on powerful X-rays to reveal the structure and behavior of atoms and molecules. Now, researchers from the Department of Energy's SLAC National Accelerator Laboratory have calculated how to make X-ray pulses at X-ray...

phys.org

New method improves proton acceleration with high power laser using frozen hydrogen as target

Bringing protons up to speed with strong laser pulses—this still young concept promises many advantages over conventional accelerators. For instance, it seems possible to build much more compact facilities. Prototypes to date, however, in which laser pulses are fired at ultra-thin metal foils...

phys.org

What do you do with a shrunken laser?

The laser is so small you need a microscope to see it properly. But it's not just the size that scientists at Sandia National Laboratories are excited about.

phys.org

 

[Forest Green]

The first one is kind of interesting, a cavity based FEL. Would the second one have an impact on some fusion reactor prototypes? The last one has lots of ramifications too.

 

[bcredman]

Laser news

Researchers show how to increase X-ray laser brightness and power using a crystal cavity and diamond mirrors

At particle accelerator facilities around the world, scientists rely on powerful X-rays to reveal the structure and behavior of atoms and molecules. Now, researchers from the Department of Energy's SLAC National Accelerator Laboratory have calculated how to make X-ray pulses at X-ray...

phys.org

New method improves proton acceleration with high power laser using frozen hydrogen as target

Bringing protons up to speed with strong laser pulses—this still young concept promises many advantages over conventional accelerators. For instance, it seems possible to build much more compact facilities. Prototypes to date, however, in which laser pulses are fired at ultra-thin metal foils...

phys.org

What do you do with a shrunken laser?

The laser is so small you need a microscope to see it properly. But it's not just the size that scientists at Sandia National Laboratories are excited about.

phys.org

The first one is not really new, but it is an interesting incremental development in work that has been ongoing since the late 2000s. See the August 2021 article https://www.science.org/content/art...smooth-out-already-revolutionary-x-ray-lasers which states "...because an XFEL uses fluctuations in the density of the electron beam to begin to generate x-rays, one pulse varies from another in intensity, and each pulse has a wide and randomly distributed spectrum of wavelengths. To squelch such noise, physicists have turned to an idea kicked around for decades, says Kwang-Je Kim, an accelerator physicist at Argonne National Laboratory. “People talked about it from time to time over drinks, but it was party conversation,” he says. “Nobody did any serious calculations” until the late 2000s, when Kim and others tackled the issue...

The idea is to extract part of the x-ray pulse generated by one bunch of electrons and feed it back to the entrance of the undulators just in time to overlap with the next bunch of electrons. The recirculated x-rays would serve as a seed that causes the electrons to radiate more predictably. In repeated cycles, the x-ray pulses should become very pure and smooth, with a spread of wavelengths only 1/1000th as wide as ordinary XFEL pulses.

The plan requires very special mirrors, however. X-rays blast through most material, but for 100 years, physicists have known that a perfect crystal should reflect x-rays at certain angles, depending on the x-rays’ energy and the crystal’s structure and orientation, as the x-rays diffract off parallel planes of atoms in the crystal. The crystal also acts as a filter, as it reflects x-rays in a narrow range of wavelengths. Such crystal mirrors remained an aspiration until 2010, when Yuri Shvyd’ko, an x-ray physicist at Argonne, and colleagues showed small synthetic diamonds can reflect x-rays with 99% efficiency. Fortunately, an XFEL’s beam is less than 100 micrometers wide."

 

[bcredman]

Laser news

Researchers show how to increase X-ray laser brightness and power using a crystal cavity and diamond mirrors

At particle accelerator facilities around the world, scientists rely on powerful X-rays to reveal the structure and behavior of atoms and molecules. Now, researchers from the Department of Energy's SLAC National Accelerator Laboratory have calculated how to make X-ray pulses at X-ray...

phys.org

New method improves proton acceleration with high power laser using frozen hydrogen as target

Bringing protons up to speed with strong laser pulses—this still young concept promises many advantages over conventional accelerators. For instance, it seems possible to build much more compact facilities. Prototypes to date, however, in which laser pulses are fired at ultra-thin metal foils...

phys.org

What do you do with a shrunken laser?

The laser is so small you need a microscope to see it properly. But it's not just the size that scientists at Sandia National Laboratories are excited about.

phys.org

The third one is interesting, but it's just another of several approaches to the integration of lasers and other active devices into silicon PICs. Here is another one from a June 2023 article: https://phys.org/news/2023-06-monolithically-semiconductor-lasers-silicon-photonic.html

When I used to follow these developments closely a few years ago, there were two key issues with most of the approaches, poor coupling efficiency to the PIC waveguides and high propagation losses through the devices.

Neither article states the coupling efficiency nor the propagation losses for the devices made with these new approaches, so I would have to get the more detailed papers on these to see if they have overcome these problems. Usually, the new techniques are initially demonstrated with high losses just to prove that devices can be integrated in a silicon PIC and operate at all, and they then say more research is needed to address the high losses, but the devices with acceptably low losses are never reported. The work reported in these articles may be different, but I wouldn't bet the farm on it. Then again, a lot can happen in a few years.

 

[Forest Green]

Does the last one apply to photonic radar development?

 

[bcredman]

Does the last one apply to photonic radar development?

Yes, in that photonic integrated circuits (PIC) can be used in the photonic portion of the photonic radar rather than using discrete photonic devices.

From the Wikipedia "Photonic radar is a technique by which radar may be produced and analysed with the help of photonics rather than traditional RF engineering techniques. The frequency of the radar is still in the RF, but lasers are used to create and analyse the RF signals with high precision...Novel potential applications include non-invasive patient vital sign monitoring using a photonic chip small enough to include in a phone."

See also https://newatlas.com/electronics/advanced-photonic-radar-centimeter-scale/ which states "Ultimately, the device could fit onto a photonic chip that’s small enough to incorporate into electronic devices like a smartphone," and https://www.nature.com/articles/s41566-023-01245-6 which states "In terms of future developments towards the miniaturization of photonic systems, recent advances in the photonic integration of critical function building blocks, such as on-chip AOFSs57,58 and optical waveguide amplifiers59,60, are providing a promising technical basis with which to achieve compact size for portable sensing31,53. This photonic approach offers a new path towards high-resolution, rapid-response and cost-effective hybrid radar–LiDAR modules for distributed, contactless vital sign detection."

See also https://ieeexplore.ieee.org/document/10172467 entitled "In field demonstration of a Photonic Integrated Circuit for SAR Imaging" which states "A radar system based on silicon-on-insulator integrated circuits is tested for X-band ground based synthetic aperture radar (GB-SAR) imaging. The photonic transceiver is equipped with a moving antenna along a 3m linear stage, providing correct reconstruction of the observed scenario, generating images with cross-range resolution of 20cm."

 

[publiusr]

There was a find about using DNA scaffolding to produce a tough glass…and something about ring shaped molecules I talk about in comments here:

The best of all possible worlds – The Unwanted Blog

That might be a framework for small lasers perhaps.

 

[bobbymike]

US Army working through challenges with laser weapons

The Army is grappling with how to fight with laser weapons, as well as how to easily repair them in the field and affordably make the systems.

www.defensenews.com

 

[Forest Green]

Fighting with lasers: Army to experiment with 50kw laser combined with kinetic air defenses - Breaking Defense

“What we don't know yet from directed energy systems, necessarily, is... how to fight [with] lasers on the battlefield, how to integrate kinetic and non-kinetic effectors,” said Lt. Gen. Robert Rasch.

breakingdefense.com

Beyond 'bullet on bullet': NORTHCOM's new defense plan looks to kill missiles before they launch - Breaking Defense

"The best missile strategy is to destroy the missiles prior to launch. A focus on missile defeat could enable distributed non-kinetic systems with larger magazines and the ability to engage missiles before they can deploy complex decoys, countermeasures, maneuvers or multiple reentry vehicles,"...

breakingdefense.com

 

[bobbymike]

China Claims ‘Huge Breakthrough’ in Laser Weapon Development

China claims to have achieved a “huge breakthrough” in developing a high-powered laser weapon for military use.

www.thedefensepost.com

 

[Forest Green]

View: https://www.youtube.com/watch?v=Dd7u99t6JhU

 

[Rhinocrates]

What do you do with a shrunken laser?

The laser is so small you need a microscope to see it properly. But it's not just the size that scientists at Sandia National Laboratories are excited about.

phys.org

Oh har har.

Drunken Sailor - Wikipedia

en.wikipedia.org

 

[Forest Green]

Laser weapons 'finally' seeing 'real progress,' Missile Defense Agency official says - Breaking Defense

"There have been some really impressive results," said MDA Executive Director Laura DeSimone on recent directed energy tests.

breakingdefense.com

WASHINGTON — With directed-energy research now coming to fruition, the Missile Defense Agency is putting “increased emphasis” on development of directed-energy weapons for shooting down adversary missiles, according to a senior MDA official.

“I think part of [why] the Missile Defense Agency in the past few years kind of backed away was that technology needed still needed to mature. It needed to mature in power levels that could be delivered on target, and needed to mature and reduction of the size, weight and power requirements to produce the directed-energy effects,” explained Laura DeSimone, MDA executive director, in an online interview with Defense News today.

The Defense Department has run hot and cold on lasers and high-powered microwaves for missile defense since the dawn of Ronald Reagan’s Strategic Defense Initiative 40 years ago. In recent years, there was a burst of interest driven by Congress in 2015 that subsequently died down, only to be re-ignited during the Trump administration by then-Pentagon director of research and engineering Mike Griffin. The problem has simply been that the technology hasn’t been ready for prime time.


However in recent months, the agency has seen “that technology maturation is happening,” DeSimone said, including at the US national laboratories, the Department of Energy and within industry.

 

[publiusr]

Now to fill a Round2 D-7 model with gun powder as a target…

 

[Forest Green]

‘Bring it’: Adm. Aquilino open to greater directed-energy trials

The Pentagon for the past three years has spent an average $1 billion on the development of directed-energy weapons, according to a watchdog.

www.defensenews.com

 

[bobbymike]

Northrop Delivers ‘Phantom’ Mini Laser System to US Military

Northrop Grumman has announced the delivery of its “Phantom” miniaturized high-energy laser weapon to the US government.

www.thedefensepost.com

 

[TomcatViP]

Being led by the Directed Energy Weapons team within the MoD's Defence Equipment and Support (DE&S) organisation, the new DEW road map is intended to result in the fielding of laser DEW (LDEW) and radio frequency DEW (RFDEW) systems for air-defence and counter-unmanned aircraft system (C-UAS) applications. The work will build on prior DEW maturation and learning, including lessons learned from three capability demonstrator projects expected to start user experimentation in 2024.

UK scopes transition plan for directed energy weapons

The UK Ministry of Defence (MoD) is embarking on a three-year ‘Transition Phase' programme designed to support the development and delivery of directed energy weapon...

www.janes.com