EM wavelengths, and how they affect PDLCs and Laserheads

In Mass Effect, the "standard" point defense laser is infra-red, balancing damage with range. The Salarians (those lovable, hyper-active geniuses) use UV lasers, sacrificing some damage for 6x the range, according to the wiki anyways I don't know if that's true differential, and it could actually be bass-ackwards for all I know.


Now Honor was looking at ways to self-extend waller missile defenses organically, without going the drone turtle some have been advocating here on the forums. Now we know at least some of the energy mounts are graser, or gamma-ray laser, which still manage to have 500 k-klick range against targets protected by sidewalls.

By changing the wave lengths PDLC's operate on (cant find any reference as to what they do operate under on the wiki), to extend their range is one possibility. Extending your PDLC range gives the possibility of getting off two cycles of PDLC, instead of just one, increasing odds of picking off the missile.


Now on the offensive side, for centuries, the missile has been the X-ray, bomb pumped laser. From my (rather limited) understanding of different em wavelengths, and how missiles work in Honorverse, using X-rays has always been about blending firepower with stand-off range.

By changing the grav-lens of missiles from X-ray, to gamma-ray you'd increase damage per lance, at the expense of having to close even closer to the ship. Not outrageously hard for the Grand Alliance, with all the Ghost Rider-spawned FTLs and ACM missiles.

Or by changing from X-ray to UV, or maybe even Infrared, you'd increase the stand-off range still further. Sacrifice some damage on a missile by missile basis, but damage per launch would go up, due to less missiles being engaged by active defense PDLC's and CMs'.

Either way you change missiles, any hostile opponent from MAlign, to SLN, to run of the mill pirates, is going to have (tree-)kittens. Whether it's because missiles are detonating right in their teeth, and GA Heavy Cruisers are firing Gamma-Ray Pumped Laserheads, doing similar damage to full waller X-ray Pumped Laserheads. Or missiles detonating so far out, they can no longer intercept any of them.


Thoughts, suggestions, comments of "Go to sleep Som, you're drunk and retarded!" (Ok, maybe not that last one, I can take constructive criticism )

Somtaaw wrote:Stuff deleted for brevity

A few points:
1) Missiles dont use grav lenses the way shipboard broadside mounts do. They use lasing rods. The exact frequency of the beam is determined by the composition of the rods. Trying to put a grav lens into a missile would not work with anything resembling current laserhead designs.

2) Grasers are known for having far more mass requirements than lasers. There appears to be a rather large minimum mass requirement. They scale *up* decently, but now down. This would also rule out grasers in PDLC installations. It's been mentioned off hand, but there two significant issues in pushing beam ranges out: Aiming, and sufficiently tight beam focus to avoid spreading out. Both of which require mass. IIRC we have a comment from RunsForCelery somewhere to the effect that even broadside grasers have issues past 1 mil KM.

Somtaaw wrote:In Mass Effect, the "standard" point defense laser is infra-red, balancing damage with range. The Salarians (those lovable, hyper-active geniuses) use UV lasers, sacrificing some damage for 6x the range, according to the wiki anyways I don't know if that's true differential, and it could actually be bass-ackwards for all I know.


Now Honor was looking at ways to self-extend waller missile defenses organically, without going the drone turtle some have been advocating here on the forums. Now we know at least some of the energy mounts are graser, or gamma-ray laser, which still manage to have 500 k-klick range against targets protected by sidewalls.

By changing the wave lengths PDLC's operate on (cant find any reference as to what they do operate under on the wiki), to extend their range is one possibility. Extending your PDLC range gives the possibility of getting off two cycles of PDLC, instead of just one, increasing odds of picking off the missile.


Now on the offensive side, for centuries, the missile has been the X-ray, bomb pumped laser. From my (rather limited) understanding of different em wavelengths, and how missiles work in Honorverse, using X-rays has always been about blending firepower with stand-off range.

By changing the grav-lens of missiles from X-ray, to gamma-ray you'd increase damage per lance, at the expense of having to close even closer to the ship. Not outrageously hard for the Grand Alliance, with all the Ghost Rider-spawned FTLs and ACM missiles.

Or by changing from X-ray to UV, or maybe even Infrared, you'd increase the stand-off range still further. Sacrifice some damage on a missile by missile basis, but damage per launch would go up, due to less missiles being engaged by active defense PDLC's and CMs'.

Either way you change missiles, any hostile opponent from MAlign, to SLN, to run of the mill pirates, is going to have (tree-)kittens. Whether it's because missiles are detonating right in their teeth, and GA Heavy Cruisers are firing Gamma-Ray Pumped Laserheads, doing similar damage to full waller X-ray Pumped Laserheads. Or missiles detonating so far out, they can no longer intercept any of them.


Thoughts, suggestions, comments of "Go to sleep Som, you're drunk and retarded!" (Ok, maybe not that last one, I can take constructive criticism )

The biggest issue of range in Honorverse is grav focusing. In real life we shoot lasers at the Moon to measure the distance. They will send a 1 gigawatt laser to the Moon. It will have around 200 quadrillion photons towards the Moon and only 1 to 3 photons will be reflected back to the sensor on Earth. While lasers seem tightly focused here on Earth, at interplanetary distances they spread out quite far.

Apollo 11 Mission - Science Experiments - Laser Ranging Retroreflector wrote:Laser beams are used because they remain tightly focused for large distances. Nevertheless, there is enough dispersion of the beam that it is about 7 kilometers in diameter when it reaches the Moon and 20 kilometers in diameter when it returns to Earth.

The Moon is roughly 1.28 light seconds away on average and the effective engagement range for Honorverse energy weapons is around 1.6 light seconds. I don't think the frequency of the beam is going to affect this much, when the dispersion of the beam is soo much greater at distance.

ericth wrote:

Somtaaw wrote:Stuff deleted for brevity

A few points:
1) Missiles dont use grav lenses the way shipboard broadside mounts do. They use lasing rods. The exact frequency of the beam is determined by the composition of the rods. Trying to put a grav lens into a missile would not work with anything resembling current laserhead designs.

Yeah, for this point I understand that missiles don't actually have grav lensing. But changing the lasing rod for something that would produce a different wavelength lance still fills the suggestion of altering performance.

I'm speculating on whether with ACMs, and FTL's, whether missiles (and PDLCs) may undergo as drastic a change as what happened when SD(P) and sister ships CLAC and BC(P) came out to play with older designs.

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Kizarvexis wrote:The biggest issue of range in Honorverse is grav focusing. In real life we shoot lasers at the Moon to measure the distance. They will send a 1 gigawatt laser to the Moon. It will have around 200 quadrillion photons towards the Moon and only 1 to 3 photons will be reflected back to the sensor on Earth. While lasers seem tightly focused here on Earth, at interplanetary distances they spread out quite far.

The Moon is roughly 1.28 light seconds away on average and the effective engagement range for Honorverse energy weapons is around 1.6 light seconds. I don't think the frequency of the beam is going to affect this much, when the dispersion of the beam is soo much greater at distance.

This is a good point, however in Honorverse even simple military grade lasers are still good at the sub-million km range, engagements from pre-Buttercup like the Battle of Cerberus.

Laser/Graser main energy mounts, should stay as is, because those fill a very specific role. But PDLC's on the other hand, are the only defense people haven't considered changing to adapt to the new combat environment.

If an attack missile managed to break through the countermissile engagement zone, the last line of active defense was the point defense laser cluster. A laser cluster was a grouping of a number of individually weak lasers, much weaker than an anti-ship laser. While this reduced the range, it allows for a higher refire rate per cluster.

The biggest missile defense increases, has been extensive increase in counter-missile tubes, and a fairly substantial increase in range when compared pre-First Haven War, and the end of hostilities of Second Haven War.

Manticoran clusters as of 1920 PD contained eight emitters, each capable of firing once every sixteen seconds. This resulted in one shot every two seconds from each cluster mounted on a ship.

That's the only real change to PDLC's over the same duration, compared to the roughly doubled tubes for CMs, and loosely doubling of CM engagement range. PDLC's are also ammo-less, so Shrike, Ferret, and Katana's become even more deadly anti-missile/anti-LAc, because they engage from farther out with an ammo-less system.

In addition to that cover by the other's, I would recommend reading the armoring appendix in "In Fire Forged." It covers armoring against laser and graser frequencies "in universe" quite nicely. It even discussed to a degree varing weapons frequencies - If you notice, the X-ray band and (to a much greater degree) Gamma ray band is a huge expanse of frequencies. Honorverse armoring (and weapons) researchers try to discover their main enemy's systems strengths and weaknesses and optimize their systems against them, while balancing "broad spectrum" capabilities.

In short, modern Manty armor is designed to best protect against known Havenite xray laser frequencies, but still has the ability to protect against a broad spectrum of frequencies. Likewise, an RMN Laserhead may be optimized to take advantage in a weakness in known Havenite armor, but not at a loss of overall penetrating capability.

The word laser in the honorverse is shorthand for X-Ray laser. So PDLCs are xray lasers.

If honorverse lasers behave like a real world laser, it's a Gaussian beam and beam divergence is explained here: http://en.wikipedia.org/wiki/Gaussian_beam

The spot size and any given range is related to the square of diameter of the beam at the minimum point (the waist) and inversely related to the wavelenght.

So really large diameter lasers at really short wavelenghts, like 8 meter gamma ray lasers, would have absurdly minimal beam divergence at light minute ranges.

IIRC, it was decreed that honorverse grasers are not Gaussian beams. So you can't snipe at orbital infrastructure from the hyperlimit.

ericth wrote:A few points:
1) Missiles dont use grav lenses the way shipboard broadside mounts do. They use lasing rods. The exact frequency of the beam is determined by the composition of the rods. Trying to put a grav lens into a missile would not work with anything resembling current laserhead designs.

Although, IIRC, missiles do use grav lens array focusing to reduce the amount of the nuclear blast that's wasted by spreading in directions other than towards the lasing rods.

But like you said that's different than how shipboard energy mounts use grav lenses (to focus and aim the laser/graser beams).

Somtaaw--

A higher frequency gives both a higher damage and a greater range. That means that changing PDLCs from the current X-ray lasers to visible or IR lasers is counter-productive. A PDLC with a higher frequency would be larger and have a slower repetition rate. PDLCs are already pretty well optimized for their purpose, though you do see some improvement, such as the faster repetition rate that the RMN has achieved.

SWM wrote:Somtaaw--

A higher frequency gives both a higher damage and a greater range. That means that changing PDLCs from the current X-ray lasers to visible or IR lasers is counter-productive. A PDLC with a higher frequency would be larger and have a slower repetition rate. PDLCs are already pretty well optimized for their purpose, though you do see some improvement, such as the faster repetition rate that the RMN has achieved.

Ah, I see. For some reason my brain keeps trying to tell me, shorter wavelength = more damage and short range, and the opposite for longer wavelengths. That got reinforced in my head, with how laser is stimulated visible/infrared, and graser is actually gamma ray based lasers.

I think it was the bit of Honor musing that active missile defence has reached stacking penalty, and to further increase the PDLC and CM tubes is counter productive that got me thinking on this.



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kzt wrote:The word laser in the honorverse is shorthand for X-Ray laser. So PDLCs are xray lasers.

If honorverse lasers behave like a real world laser, it's a Gaussian beam and beam divergence is explained here: http://en.wikipedia.org/wiki/Gaussian_beam

The spot size and any given range is related to the square of diameter of the beam at the minimum point (the waist) and inversely related to the wavelenght.

So really large diameter lasers at really short wavelenghts, like 8 meter gamma ray lasers, would have absurdly minimal beam divergence at light minute ranges.

IIRC, it was decreed that honorverse grasers are not Gaussian beams. So you can't snipe at orbital infrastructure from the hyperlimit.

I thought the Honorverse lasers were basically very similar to current generation industrial lasers. Powerful enough to cut steel plates, but practically no range so the emitter has to be fairly close to what you plan to cut.

And in Honorverse, anything beyond a million KM is for all intents invulnverable to a pure energy weapon-armed ship, even without sidewalls. At least thats what the wiki says, fairly hard limit of about that range.

Somtaaw wrote:I thought the Honorverse lasers were basically very similar to current generation industrial lasers. Powerful enough to cut steel plates, but practically no range so the emitter has to be fairly close to what you plan to cut.

And in Honorverse, anything beyond a million KM is for all intents invulnverable to a pure energy weapon-armed ship, even without sidewalls. At least thats what the wiki says, fairly hard limit of about that range.

Think about this a bit. If the power density is sufficent at 100,000 km and 300,000 km, how much can if fall by a million km?