Defense vs laser strikes coming ! - Page 1
Forum section: electronics / general

author: 3roomlab
author_rank: Frequent Contributor
timestamp: May 03, 2018, 04:58:22 am
content: it seems this is a new innovation just release around 2017 ?they seem to be adding stuff to clear optical material and make a seemingly clear material guard against laser. the material is called "lambda guard". since it is so new, i dont suppose anybody here have tried it? or seen it in any commercial product like eye wear?http://www.metamaterial.com/about-us/if what the youtube video show is real, it means it should be applicable to wearables like welding protection ? so a welder should see the welds dimmed? this thing just screws up the logic of how light works. clear lens ... but high power laser just look like reflecting off it?

author: Brumby
author_rank: Unknown
timestamp: May 03, 2018, 07:26:04 am
content: Fascinating concept. Metamaterials bring a whole new wonderland of possibilities.The question, though, is valid:Quote from: 3roomlab on May 03, 2018, 04:58:22 amSomewhere in the dialogue, I seem to recall mention about "frequency". If I interpret that correctly, it could well mean they have a material that is opaque/reflective to a specific narrow range of light - a sort of 'notch filter' for light transmission, if you like. That being the case, then the broader spectrum is not going to be too adversely affected.If such is the case, then there will need to be specific attention given for each frequency - which may be practical for commonly available laser pointers - but it doesn't allow for anything tuned to different frequencies.QuoteI doubt it would work for such a broad spectrum.

author: tautech
author_rank: Super Contributor
timestamp: May 03, 2018, 08:38:52 am
content: The lasers in question fall into distinct wavelengths and can therefore be targeted with existing technology just adapted for aircraft use.A second or two on Google finds what they use in the commercial laser cutting industry:http://www.lasersafetyindustries.com/Glass_Machine_Laser_Safety_Windows_s/552.htm

author: technogeeky
author_rank: Frequent Contributor
timestamp: May 03, 2018, 07:16:41 pm
content: is a very good colloquium lecture about "metasurfaces". The general idea seems to be implanting nano-scale objects of various shapes, sizes, and orientations onto a clear medium (clear, at least, to the wavelengths it must pass). This clear medium can be made flexible. The total thickness of one layer of a metasurface is about 100 micrometers.There are whole classes of applications of this newly developing technology and many of them are listed in this video.This includes some pretty remarkable things like spatial separation of light polarization states (in addition to color states). It includes things like deformable lensing. It includes thing like lenses which have multiple focal depths. It's pretty remarkable technology, and pretty simple in theory.The main downside of such things is that they do not permit wide bandwidth manipulation.

author: chris_leyson
author_rank: Super Contributor
timestamp: May 03, 2018, 08:05:17 pm
content: So far I only found this from Lamda Guard Technologies Ltd CN104380147A, EP2825905A2, WO2013136035A2, WO2013136035A3 US9890925 etc. EDIT: Filters US20140293467 and EP2748655A1, metamaterials.

author: T3sl4co1l
author_rank: Super Contributor
timestamp: May 03, 2018, 08:12:45 pm
content: Nonlinear optics are nothing new, although having something tightly controlled, such that it allows full sunlight (which is nearly destructive as it is, and famously destructive when magnified a few times),without exhibiting wear(darkening, embrittlement, etc.), while blocking higher intensities (a few orders of magnitude higher), might be tricky to design. I've not heard of such a thing, but I don't have any doubt it's possible.A theoretically trivial example would be a rectenna array on an insulating substrate: when no load is applied, radiation is absorbed then retransmitted by the array. This causes scattering, which isn't unusual because the substrate has an index of refraction as well; it's simply not going to be 100% transparent, after all. (Well, you could do tricks with 1/4 wave layers -- antireflection stuff -- but hey, that's just engineering.) But short out the DC output, and it becomes opaque, reflective -- low impedance. To go between the two states automatically, simply attach a MOV!Or more likely, use diodes that are carefully built to withstand repetitive avalanche, so they do the work directly.Since the beginnings of microwave technology, there have been TR cells -- a 1/4 wave chunk of waveguide filled with neon gas or what have you -- which does this automatically, to protect the receiver from the radar pulse.Doing this at optical frequencies is hard, because metals aren't metallic up there. Some have weird permittivity, and in general, electrons themselves don't drift, their effective mass is a significant factor in the motion, making any hope of a visible rectenna quite small (not impossible, because who knows, but we have no idea right now). Still, there are probably materials that exist, or that can be formulated, which has a useful, tunable effect.Mind the problem with molecular limiters: we need a classical effect (amplitude dependency) from a quantum system (tiny molecules). It's hard to make something that doesn't degrade on a statistical, quantized basis (i.e., exposure to any radiation causes gradual breakdown of the system).Note that a one-time, charring, ablative coating is still useful, just as bullet-proof glass isn't exactly clear after (and where) it's been struck, but it still does its job blocking stuff! This probably makes ordinary plastics quite effective against IR and UV lasers at least.Tim