Modern Carrier Battle Group..Strategies and Tactics

You also seem to think that EMCON is everything. Guess what, a novice estimate of the Australian Jindalee OTH radar indicates that it can detect a CVN-size vessel at more than 2,000nm (SCS is about half that size). And that's a design from the late 80s.

I do also. Trust me on this. What Ambivalent post is only the very tip of the iceberg. Ambivalent was an Naval officer.

EP-3 huh? And the PLA happened to have spent a few days with a completely intact EP-3 that landed in Hainan a few days back. There are few better sources of intel than a complete set of hardware.

The EP-3 internal computers/electronics were not intact when the aircraft landed. There is a distruct sequence upon capture.

Originally Posted by bd popeye

I do also. Trust me on this. What Ambivalent post is only the very tip of the iceberg. Ambivalent was an Naval officer.

I know that EMCON is only 1 of the means. And it is not the only means. However, there are new search capabilities, such as SAR.

pops, you have CVN experience. And as I said earlier, the South China Sea (SCS) is ~ 1,000nm by 800nm (from Vietnam to the Philippines and from Hainan to East Malaysia). The heavily monitored Spratlys is smack in the middle of this. So, will a CBG hide between Hainan and Spratlys? Or south of Spratlys? From your conclusion, where do you think PLA will focus their search efforts?

Given the geography of SCS and the presence of a large number of PRC-owned commercial shipping, you think it is possible to hide a CBG there?

I have no intention of repeating my earlier points ad nauseam. I just want to caution that US intel estimates have consistently underestimated PRC's capabilities/achievements. And this may just be another point in that trend.

Originally Posted by bd popeye

The EP-3 internal computers/electronics were not intact when the aircraft landed. There is a distruct sequence upon capture.

And from media reports from that time, it seems that the destruct sequence wasn't carried out as thoroughly as it should have been. Anyway, I doubt that either side will reveal the extent of intel gained/lost in the open any time soon.

Originally Posted by Spartan95

By the way, I spent a year experimenting with lasers in a laser lab. So yes, I do know what I'm talking about.

That's nice that you spent a whole year in a "laser lab" and thus know what you are talking about. I have decades of daily ongoing experience actually building solid state laser systems for a very wide variety of end users. I doubt your year of photonics and electro-optics experience in the "laser lab" can hold a candle to my career specific knowledge.

That said, I enjoy your skepticism, it is entertaining in a Tokyo Rose kind of way. I do hope you consider a career in the photonics industry, as the pay and career opportunities are extraordinarily rewarding at this time. With that knowledge you will learn what role capacitors play in megawatt solid state electro-optic systems. And rest assured, last year's public demonstration of the navalized laser system was not the most powerful system that has been built by the US for that purpose.

Lasers are not the be all and end all of all of weapon systems and tactics, as no single weapon platform is. Lasers are here to stay and laser weapon systems will continue to be developed until its full potential is realized. The new Ford Class carriers that the US is building is anticipating tactical laser systems to be integrated throughout the ship. Poo-poo tactical lasers at your own risk.

So often in war, you just cannot predict what is going to happen until fate tips the dice so to speak. Sure, the USN could get pretty close to the Chinese coast without being detected. Sure, the Chinese could detect the USN pretty far out. Which of those outcomes happens depends on the skill of the men handling the machines and making the decisions, as well as pure turns of luck. I'm reminded of the Battle of Midway. The US dive bomber attack which won the battle for the US was about to turn back for their carriers without having found their targets as they ran low on fuel. The flight commander, C. Wade McClusky, decided to press on for 10 mins on a whim and a hunch. He found the Japanese fleet and within minutes the cream of the IJN was a burning slick on the water.

Had he turned around, the Japanese would have recovered aircraft and launched an attack which most likely would have found the US fleet and the battle would have gone the other way. Before the war people of course had endless discussions like this one, analyzing every aspect of a confrontation between the fleets. But in the end it came down to that one decision, more or less. Untangling causation and coincidence in matters of war is always pretty much impossible.

Originally Posted by jantxv

That said, I enjoy your skepticism, it is entertaining in a Tokyo Rose kind of way. I do hope you consider a career in the photonics industry, as the pay and career opportunities are extraordinarily rewarding at this time. With that knowledge you will learn what role capacitors play in megawatt solid state electro-optic systems. And rest assured, last year's public demonstration of the navalized laser system was not the most powerful system that has been built by the US for that purpose.

I am actually well aware that this is by no means the most powerful laser that the US has built.

However, as the 2nd video you posted indicated, the current laser system requires the CIWS to designate a target to it. Which means it is not a stand-alone system that the CIWS is. There is also no mention of how much power it needs and what that translates to in terms ship space onboard a warship (for extra power generation capacity).

Not much use if the laser can't be powered by the power generators on smaller ships (such as frigates) that make up the bulk of any navy is there?

Originally Posted by jantxv

Lasers are not the be all and end all of all of weapon systems and tactics, as no single weapon platform is. Lasers are here to stay and laser weapon systems will continue to be developed until its full potential is realized. The new Ford Class carriers that the US is building is anticipating tactical laser systems to be integrated throughout the ship. Poo-poo tactical lasers at your own risk.

As I stated in a separate thread, I have no doubt that lasers are the future. Just not on the surface of the earth. They are ideal weapons for use in space where there is no weather. But there are serious limitations when used within the troposphere.

As for the new Ford class CVNs, how many will be built? These are nuclear powered warships which don't have much of a power generation limitation. Unfortunately, the reality is that all other warships have serious limits on how much power they can generate for their weapons on sensors. This is why up to now, Aegis systems can only be fielded on destroyers and not frigates. They use up too much power (although the Europeans have what they claim to be a "mini-Aegis" in a frigate with a Phased Array Radar that operates in the I-band).

Now, back to lasers itself in the maritime environment. As mentioned earlier, smoke has a detrimental effect on lasers. And a warship generates a heck of a lot of smoke when it is in action. Missile firings generate smoke. Gun firings generate smoke (including CIWS). Sudden acceleration of the ship generates smoke. How effective do you honestly think a laser will be in that kind of environment? Or perhaps all military munitions should be designed to be smokeless to facilitate laser weapons?

Than, there is the issue of rain and fog, which will adversely affect the performance of lasers. And since you have so much experience in lasers, why don't you elaborate on the effects that these have on lasers? Or is there such a thing as a laser that can penetrate fog/rain/smoke and still be effective at destroying a target several miles out?

Also, in the maritime environment, there is such a thing as salt desposits when a ship has been out at sea for some time. Salt deposits are very bad for optics. Sure, the laser lenses can be cleaned prior to firing. However, any residual desposits will affect the performance of the laser itself, unless the cleaning process is 100% thorough. Not an easy assurance for a maritime environment, particularly during typhoon season.

That video clip about lasers shooting down that drone is typical of the kind of positive spin put onto a developing capability. I recall vividly the positive spin of the Crusader liquid propellant artillery system that cost US$12 billion that was eventually abandoned with not a single operational system deployed.

Since the laser weapon is a next gen weapon, let's look at what a next gen threat looks like and whether it will be able to handle the threat. BrahMos is indicative of what next gen anti-ship threats will look like.



This thing weighs 3 tons, travels at up to Mach 3 and have a range of ~290km. It also has vernier thrusters, as shown in that clip, which makes it very manoeuvrable. It is currently operational.

A hypersonic variant with Mach 5+ is allegedly under development.

A 3 ton mass flying at Mach 3 towards its target is not going to be stopped by a laser in the fashion shown in the shooting down of the drone simply because the Brahmos' engine is not going to be visible to the laser. Even if the laser has enough time to destroy the seeker head, the missile will still have enough kinetic energy to carry it to its target. And cause serious damage even if the warhead doesn't blow because the rocket engine will still be burning.

Oh, and the older supersonic Yakhont (3-ton, Mach 2.5) is still in service. Heck, Vietnam and Indonesia actually have these missiles.

How good are lasers going to be against such massive, supersonic anti-ship threats?

Another clip showing the Brahmos:

This thing weighs 3 tons, travels at up to Mach 3 and have a range of ~290km. It also has vernier thrusters, as shown in that clip, which makes it very manoeuvrable. It is currently operational.

I think the vernier thruster will be only used for the initial launch, and won't play much of a role in the actual terminal phase, correct me if I'm wrong.

A 3 ton mass flying at Mach 3 towards its target is not going to be stopped by a laser in the fashion shown in the shooting down of the drone simply because the Brahmos' engine is not going to be visible to the laser. Even if the laser has enough time to destroy the seeker head, the missile will still have enough kinetic energy to carry it to its target. And cause serious damage even if the warhead doesn't blow because the rocket engine will still be burning.

If the seeker head's destroyed, and the target ship is still powered then it should be able to manouever out of the missile's final trajectory? Or maybe not, considering how fast the missile would be in the first place. But the laser would be a hard kill and should cause the missile to veer off course at least.

I'm not sure how powerful a laser has to be to cause a minimum hard kill for say, the Brahmos -- 100 kw? 200?

Oh, and the older supersonic Yakhont (3-ton, Mach 2.5) is still in service. Heck, Vietnam and Indonesia actually have these missiles.

How good are lasers going to be against such massive, supersonic anti-ship threats?

Burn through the surface, ignite the propellant? Boom? There will be detriments (fog, cloud etc, as you said) and some countermeasures (surface coatings and the like) which may limit the laser's potential, but they will keep getting more powerful and imho I think you're kidding yourself if you think lasers will not supplement or even supercede conventional ciws systems within the coming decades.

It's just my 2 cents anyway. :/

In other news...

New missile 'ready by 2015' - GlobalTimes

New missile 'ready by 2015'

By Zhang Han and Huang Jingjing
The Chinese army is researching a new type of conventional missile that is set to be weaponized and entered into active service within five years, military sources have revealed.
China Aerospace Science and Industry Corporation (CASIC), the nation's largest missile weaponry manufacturer, is set "to complete research, production and delivery of this new generation of missile by 2015," the China News Service reported Thursday.
The new missile would be part of a network forming a solid defense system allowing for total coverage in both defense and attack, and capable of dealing with various threats from land, sea, air, space as well as cybernetic attacks, according to the report.
The report, however, did not provide any further details of the new missile.
A military source close to the development, speaking on condition of anonymity, confirmed to the Global Times yesterday that "The subject under development is a medium- and long-range conventional missile with a traveling distance of as far as 4,000 kilometers."
"The research is going smoothly, and the missile will be produced and ready for service in five years," he said, noting that the project would also entail a three-year evaluation period.
"It extends the range of China's missiles and will therefore greatly enhance the national defense capabilities," the source said.
The source also unveiled that "the Chinese-made Dong Feng 21D missile, with firing range between 1800 and
2800 kilometers, is already deployed in the army."
Foreign media have also speculated that the Dong Feng 21D is a "carrier killer" and would prove to be a game-changer in the Asian security environment, where US Navy aircraft carrier battle groups have ruled the waves since the end of World War II, the AP reported.
China debuted its first stealth fighter jet, the J-20, in January, in a test flight that coincided with a visit to Beijing by US Defense Secretary Robert Gates.
Following the successful test flight, speculations and assessments of Beijing's military advancement echoed around the world.
The Pentagon this week formally rolled out a record base budget for fiscal year 2012 of $553 billion, up $22 billion from the level enacted for 2010. However, additional overseas war funding is down by $41.5 billion.
This led Gates to counter-attack, warning Congress on Wednesday against making deeper spending cuts than those already proposed, telling lawmakers that the US faces threats ranging from militants to states "developing new capabilities that target our traditional strengths," citing Iran, North Korea, as well as China, Reuters reported.
Li Daguang, a military expert at the People's Liberation Army National Defense University, told the Global Times that Thursday's revelation speaks volumes about the significant progress China had made in the field of missile technology as well as proving the country's commitments to transparency in military affairs.
"But the real combat capabilities of the missile in complicated situations remains to be tested. There is still a huge gap between China and Western countries with regard to advanced weaponry development," he said, adding that China should always remain prudent and rational when presenting its military progress.
Wang Yanan, an associate editor-in-chief at Aerospace Knowledge magazine, told the Global Times that some seem to favor wild speculation where the Chinese military is concerned.
"US wariness doesn't suggest its inability to develop advanced missiles. The US is still a leader in this aspect as it possesses the most cutting-edge missile technologies," Wang said.
Song Shengxia contributed to this story

4000km ranged AShBM anyone?
Regardless this weapon will just add to the A2D capability of the 2nd Artillery, though I'm not sure what the article means by "total coverage in both defense and attack, and capable of dealing with various threats from land, sea, air, space as well as cybernetic attacks"

The statement "total coverage in both defense and attack" says to me that the missile will have numerous variants for land and sea and space (conventional ballistic missile/AShBM/ASAT respectively) and even air, to an extent if we classify ICBMs and IRBMs as air... but cybernetic? Does that imply it's more secure from cyber threats as in... better onboard guidance or such?

Either way it's good news, as other countries are beefing up their anti missile capabilities, and shows that China's still developing and looking into the future for their next generation systems.

Thoughts, anyone?

EDIT: My bad, this new missile is meant to be part of a "network" with defense and attack... not necessarily meaning the missile itself will be capable of defense and attack. I kind of get why the US keeps calling for more transperancy, it gets quite frustrating trying to read between the lines all the time.

Originally Posted by Bltizo

I think the vernier thruster will be only used for the initial launch, and won't play much of a role in the actual terminal phase, correct me if I'm wrong.



If the seeker head's destroyed, and the target ship is still powered then it should be able to manouever out of the missile's final trajectory? Or maybe not, considering how fast the missile would be in the first place. But the laser would be a hard kill and should cause the missile to veer off course at least.

I'm not sure how powerful a laser has to be to cause a minimum hard kill for say, the Brahmos -- 100 kw? 200?



Burn through the surface, ignite the propellant? Boom? There will be detriments (fog, cloud etc, as you said) and some countermeasures (surface coatings and the like) which may limit the laser's potential, but they will keep getting more powerful and imho I think you're kidding yourself if you think lasers will not supplement or even supercede conventional ciws systems within the coming decades.

It's just my 2 cents anyway. :/

The vernier engine will be solid propellant, so indeed only used during launch.
Lasers provide very little impulse. Burning out the seeker will not change the trajectory of the missile. But if the trajectory is good one kilometer and second from impact the ship is unlikely to maneuver out of the way.
So I think at that stage you want the fastest possible material defense. What about a 40 mm gun firing sub caliber shot, as used by modern tank guns?

Re: 4000 km AShBM

This contains two translations, from the source to the news item in Chinese then into English. So: we can't know.
DF-21D has a range of 1800-2800 km is a relatively simple sentence.. That means the missile has a range 1800 km and fire control sees out 2800 km or it means we won't tell or even something else.

Originally Posted by Bltizo

I think the vernier thruster will be only used for the initial launch, and won't play much of a role in the actual terminal phase, correct me if I'm wrong.

Beats me really. There is no public information on how the vernier thrusters will be used. And the way the video shows the the thrusters being used, I doubt that they are 1-time use only. There is just not enough information on it either way.

Originally Posted by Bltizo

If the seeker head's destroyed, and the target ship is still powered then it should be able to manouever out of the missile's final trajectory? Or maybe not, considering how fast the missile would be in the first place. But the laser would be a hard kill and should cause the missile to veer off course at least.

The BrahMos travels at Mach 3, which means ~1km per second (Mach 1 is ~330m/s). If a laser takes 10 secs to destroy the seeker head, the missile would have travelled ~10km.

Whether the missile's trajectory is affected depends on how the missile is programmed to react when it loses its seeker head. It can be programmed to just continue the original trajectory. And this seems like a fairly simple solution to laser based defence.

Originally Posted by Bltizo

I'm not sure how powerful a laser has to be to cause a minimum hard kill for say, the Brahmos -- 100 kw? 200?

Quite a few factors involved, with perhaps the most important being range to target, and time needed to cause damage by the laser on the target. 100kW or 200kW laser may not be powerful enough to damage the BrahMos sufficiently in a short period of time (i.e., less than 10 sec).

Even if the laser has an effective range of 20km, it will be constrained by line of sight issues (due to the sea skimming nature of BrahMos, the engagement horizon is likely to be less than 20km anyway). Thus, the laser needs to be able to destroy the BrahMos quickly before it gets into the terminal dive phase. Assuming the engagement horizon to be 15km, the laser need to destroy the missile before it gets too close. There are 2 important factors to consider here:
1. How powerful is the laser at 15km?
2. How much atmospheric scattering is there?

In some places and depending on season, visibility is less than 15km due to pollution, haze, and any other number of atmospheric factors. This reduces the effective range of lasers.

There is also the issue of power efficiency of lasers. Currently, if I'm not mistaken, most lasers have efficiency of ~30%. That means that for a 100kW laser output, it needs to be powered by more than 300kW of energy. This is 1 of the key limiting factors why laser weapons are not widely used, particularly on ships. Given the foreseeable technological advancements, laser weapons are only practical on nuclear powered vessels (such as an aircraft carrier) in the next few years. Smaller ships simply don't generate enough power for lasers.

Originally Posted by Bltizo

Burn through the surface, ignite the propellant? Boom? There will be detriments (fog, cloud etc, as you said) and some countermeasures (surface coatings and the like) which may limit the laser's potential, but they will keep getting more powerful and imho I think you're kidding yourself if you think lasers will not supplement or even supercede conventional ciws systems within the coming decades.

It's just my 2 cents anyway. :/

The issue for trying to ignite the propellant of a missile coming directly towards the laser platform is that the propellant is behind the warhead, which is behind the seeker head. Thus, to get through to the propellant of an incoming missile requires the laser to burn through close to half the length of the missile itself. Not exactly a quick method.

And here's a list of possible counter-measures listed on Wiki for Tactical High Energy Laser:

1. Reflective coatings which attempt to reflect a large proportion of the incident radiation which is incident upon the aimed projectiles.
2. Modification of projectile geometries to take into account the possibility that laser light radiation might be used to neutralize the projectiles.
3. Enveloping gas/substance the use gaseous envelopes around a missile would ensure that a sufficiently cool gas will carry away a portion of the incident radiation energy which is incident upon the missile by both convective and diffusive effects.
4. An oscillating or chaotic trajectory will increase the difficulties in the use of the THEL system due to guidance. If guided into windy or turbulent environments, such a chaotic trajectory would also ensure that there is more of a turbulent gaseous flow around the missile.
5. Heat Resistant Coating Layers (HRCLs). Similar to reflective coatings. However, in the case of HRCLs, internal capillaries/coolant mechanisms could ensure that excessively large amounts of heat could be dissipated.
6. Multi-stage projectile systems which “dummies” a THEL kill.

Originally Posted by Bltizo

In other news...

New missile 'ready by 2015' - GlobalTimes




4000km ranged AShBM anyone?
Regardless this weapon will just add to the A2D capability of the 2nd Artillery, though I'm not sure what the article means by "total coverage in both defense and attack, and capable of dealing with various threats from land, sea, air, space as well as cybernetic attacks"

The statement "total coverage in both defense and attack" says to me that the missile will have numerous variants for land and sea and space (conventional ballistic missile/AShBM/ASAT respectively) and even air, to an extent if we classify ICBMs and IRBMs as air... but cybernetic? Does that imply it's more secure from cyber threats as in... better onboard guidance or such?

Either way it's good news, as other countries are beefing up their anti missile capabilities, and shows that China's still developing and looking into the future for their next generation systems.

Thoughts, anyone?

EDIT: My bad, this new missile is meant to be part of a "network" with defense and attack... not necessarily meaning the missile itself will be capable of defense and attack. I kind of get why the US keeps calling for more transperancy, it gets quite frustrating trying to read between the lines all the time.

Sometimes I have to wonder how much of the press from the 2nd Artillery are driven by inter-service rivalries and self promotion as opposed to actual usable hardware. Absent demonstrations of capability it's difficult to determine.

Originally Posted by Ambivalent

Sometimes I have to wonder how much of the press from the 2nd Artillery are driven by inter-service rivalries and self promotion as opposed to actual usable hardware. Absent demonstrations of capability it's difficult to determine.

Considering how much coverage the PLA and 2nd Arty respectively get (both very little) I think not many if any of the press would be due to that.
I mean the Chinese military isn't known for exaggerating their hardware and development, and usually underplay them if anythng to get potential foes to underestimate true capabilities so most of the time when there's a media disclosure it means the specified weapon system should be quite far in development.

Originally Posted by Spartan95

Beats me really. There is no public information on how the vernier thrusters will be used. And the way the video shows the the thrusters being used, I doubt that they are 1-time use only. There is just not enough information on it either way.



The BrahMos travels at Mach 3, which means ~1km per second (Mach 1 is ~330m/s). If a laser takes 10 secs to destroy the seeker head, the missile would have travelled ~10km.

Whether the missile's trajectory is affected depends on how the missile is programmed to react when it loses its seeker head. It can be programmed to just continue the original trajectory. And this seems like a fairly simple solution to laser based defence.



Quite a few factors involved, with perhaps the most important being range to target, and time needed to cause damage by the laser on the target. 100kW or 200kW laser may not be powerful enough to damage the BrahMos sufficiently in a short period of time (i.e., less than 10 sec).

Even if the laser has an effective range of 20km, it will be constrained by line of sight issues (due to the sea skimming nature of BrahMos, the engagement horizon is likely to be less than 20km anyway). Thus, the laser needs to be able to destroy the BrahMos quickly before it gets into the terminal dive phase. Assuming the engagement horizon to be 15km, the laser need to destroy the missile before it gets too close. There are 2 important factors to consider here:
1. How powerful is the laser at 15km?
2. How much atmospheric scattering is there?

In some places and depending on season, visibility is less than 15km due to pollution, haze, and any other number of atmospheric factors. This reduces the effective range of lasers.

There is also the issue of power efficiency of lasers. Currently, if I'm not mistaken, most lasers have efficiency of ~30%. That means that for a 100kW laser output, it needs to be powered by more than 300kW of energy. This is 1 of the key limiting factors why laser weapons are not widely used, particularly on ships. Given the foreseeable technological advancements, laser weapons are only practical on nuclear powered vessels (such as an aircraft carrier) in the next few years. Smaller ships simply don't generate enough power for lasers.



The issue for trying to ignite the propellant of a missile coming directly towards the laser platform is that the propellant is behind the warhead, which is behind the seeker head. Thus, to get through to the propellant of an incoming missile requires the laser to burn through close to half the length of the missile itself. Not exactly a quick method.

And here's a list of possible counter-measures listed on Wiki for Tactical High Energy Laser:

1. Reflective coatings which attempt to reflect a large proportion of the incident radiation which is incident upon the aimed projectiles.
2. Modification of projectile geometries to take into account the possibility that laser light radiation might be used to neutralize the projectiles.
3. Enveloping gas/substance the use gaseous envelopes around a missile would ensure that a sufficiently cool gas will carry away a portion of the incident radiation energy which is incident upon the missile by both convective and diffusive effects.
4. An oscillating or chaotic trajectory will increase the difficulties in the use of the THEL system due to guidance. If guided into windy or turbulent environments, such a chaotic trajectory would also ensure that there is more of a turbulent gaseous flow around the missile.
5. Heat Resistant Coating Layers (HRCLs). Similar to reflective coatings. However, in the case of HRCLs, internal capillaries/coolant mechanisms could ensure that excessively large amounts of heat could be dissipated.
6. Multi-stage projectile systems which “dummies” a THEL kill.

A couple of comments. The distributed electrical system of the Ford class CVN is designed specifically to support the power demands of future directed energy systems. The same is true of the DDG-1000 class and the Type 45's in RN service. These ships were designed with an eye on future conversions as directed energy systems and rail guns come on line.

The little laundry list mentioned above ignores the detail that space and weight are in very short supply on a missile. Everything mentioned will detract from the speed, payload and range to a greater or lesser degree. Analysts will study the degree which each of the mentioned "countermeasures" buys effectiveness against the performance that has to be sacrificed. If you notice, there are few if any anti-ship missiles equipped with countermeasures simply because there is no room or payload for these. Speed, stealth and/or terminal maneuvers are about all that can be built into a practical air to surface or surface to surface weapon.
Missiles weight and dimensions are determined by existing VLS cell dimensions and maximum weight limits. Air launched missiles have to be compatible with the launch aircraft and available launch rails. Unless the mission is so critical the user is willing to pay for a major modification program for the launch platforms, most missiles end up being limited in size, payload and maximum range by the platform that launches it.
Enveloping the missile in a cool gas? Laughable. Does the person who wrote this understand the difficulty there is just keeping an IR sensor cooled long enough to complete the flight of a missile? Where is all this cooling gas going to be stored? Has this author ever seen an argon bottle from an IR missile and understand how it operates or how long the gas lasts, even when metered in the minute amounts necessary to cool a typical IR seeker?

There are few if any anti-ship missiles equipped with countermeasures simply because there were few defenses to protect the missile against.
The IR seeker can be cooled by expanding pressurized carbon dioxide. The cooling gas for the missile is mostly likely steam, generated from water heated by the incident laser energy.