Rolls-Royce Making Progress on 100-kilowatt Combat Lasers

Rolls-Royce LibertyWorks has achieved significant technology milestones for integrated power and thermal management system for high-power defensive 100-kilowatt combat lasers.

They have electrical power, thermal management capacity, temperature management and control, instantaneous power availability and continuous operations.

The Rolls-Royce lasers are small and light enough to fit in US Army vehicles and US Navy ships. They want to make modular integrated power and thermal management capabilities with multiple applications such as US Army Family of Medium Tactical Vehicles, Navy Littoral Combat Ship, or base defense protection.

22 thoughts on “Rolls-Royce Making Progress on 100-kilowatt Combat Lasers”

  1. Well, you have a point, but they don’t specify how rainy it was when the tests were conducted, nor how far away the targets were. Obviously, the heavier they rain and the further the target, the more the beam would be dispersed by the dropplets. So perhaps the system can cope wtih some level of rain, but heavier rain would cause the system to loose efficiency.

  2. This source supports my assumption that rain drops fall faster than 160 mm per second, no?

  3. 1) “…not a replacement for guns at this time.”
    2) “…close to useless in rain or fog.”
    3) “The side with high tech would be defenseless.”


    Falling raindrops hit 5 to 20 mph speeds. … “At sea level, a large raindrop about 5 millimeters across (house-fly size) falls at the rate of 9 meters per second (20 miles per hour). Drizzle drops (less than 0.5 mm across, i.e., salt-grain size) fall at 2 meters per second (4.5 mph).”

  5. We need a super slow motion video of a laser slowly eroding a rail gun sabot travelling at mach 7.

  6. I’ve often wondered if it wouldn’t be better to mount such a laser on something like an F-15, B1, or B52 to basically act as a “missile sponge”. It would create a very frustrating environment for the defending force where there’s a high chance that your SAMs won’t actually be effective against what you can “see.”

  7. Did I state that the article claimed that laser weapons would replace all other weapons systems? No?

    I did claim that he efficacy of the laser system would be very limited, and you do not seem to be arguing otherwise.

    I do believe that laser can be an effective fair-weather weapons system, if they manage to increase the average power and, more importantly, the peak power. If you can maintain an average power of 100 kW, but have a peak power of 100 MW (i.e. a duty cycle of 0.1%), then it would be much more difficult to polish the target to reflect the incident beam. At some threshold power the mirror surface would turn into plasma…

  8. I don’t think so, but if you have a source for this claim, I am ready to be convinced otherwise. Each droplet should act as a lens/dispersion point, so that the laser light beyond the droplet is unfocused. Since the droplet is transparent, very little of the beam energy will be deposited in the drop.

    Lets say 1% is deposited and that the droplet diameter is 2 mm ==> 0.004 grams of water. A gram of water needs ~2600 J to evaporate (starting at 20 deg Celsius) ==> 10.5 J for the droplet. Assuming the droplet stays 0.1 seconds in the beam and only 1% is deposited, you need 10500 W per droplet. This equates to a cross section energy density of 10500 W / [area one droplet] = ~48 kW/mm2. This would make the beam ~2 mm in diameter. Completely unrealistic.

    At the other end, if we assume that *all* of the laser beam is deposited in the droplet, we get 0,48 kW/mm2. But even in this case the laser would need to be concentrated in a cross section of ~200 mm2, or equivalently, have a diameter of 16 mm. And the droplet would be dropping really slowly to stay in the beam for 0.1 seconds, about 160 mm second. Again completely unrealistic, both from droplet speed and beam diameter.

    So from physics, there is no way you could be correct. (I don’t get me started on the optical effects of the evaporated water… )

  9. A 100KW laser will vaporize everything like fog or rain on its path if it is correctly focused.

  10. I read the article…nowhere in there does it say: “We will be getting rid of all our other weapons immediately”. Just as bullets and missiles have different strengths and weaknesses, so will a laser. The trick will be to effectively integrate the laser into a weapon system, deciding which weapon is best to engage a target.

    The important takeaway from this article is that a laser needn’t rely on the host vehicle’s electrical system. It could be installed on current ships and trucks instead of waiting for the next generation coming out with higher power generation systems. Still too big for a fighter…or even bomber at this point, but it might fit into a special ops C-130…hmmm.

  11. Mr. Wang, this new format of presenting your work is unfortunate, to small and without references, we all understand you live of this but the previous design was much more interesting.

  12. Well, 100 kW may shoot down missiles and blind sensors, but they are not a replacement for guns at this time. I don’t think it would be able to shoot down aircraft, let alone tanks. Let us not forget that all laser system must be close to useless in rain or fog. Come to think of it, it could be a future tactic of a combatant with lower tech to wait for rain and then attack. The side with high tech would be defenseless….

  13. Well for one thing the fusion reactor lasers such as at National Ignition Facility are the size of buildings, which would be tricky to mount on a ship, let alone a plane.

    Secondly the NIF lasers don’t actually have that much energy in them. The wikipedia page claims a mere 4 MJ, which is about the same as you’d get eating a decent meal. It is however extremely focussed, both in space and time, to give incredible power densities at the tiny fuel pellets they use.

  14. We seem to hear a lot about these combat lasers but get no gratuitous video of them blasting stuff.

  15. What is the difference between these and the lasers they are using to try to make a fusion reactor?

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