Greetings from a older guy with three decades in this business.
During that time, I assisted ILDA as a member of ILDA with regards to lasers in airspace, worked with audience scanning lasers for laser shows, and worked for a subcontractor on reviewing a little something for the US Military. I'm a certified LSO
I also have a retinal burn from long, long ago, when a laser operator went past a lock-out tag I had on a system, turned a system key 1000 feet away from where I was working at. The result of that action resulted in a series of beamtable actuators all popping up, and a I have a small burn in my right eye from a idling large frame ion laser. A laser that for its size, has impeccable beam qualities that will never fit in a handheld. Hence a tiny black spot appearing in my peripheral that was annoying for years. That was decades ago.
Lets address some things without my making it "too easy" for the bad guys.
So, Dazzlers..
Factoid, Without breaking my NDA, I would tell the OP to go look at the huge lens diameter on a commercial dazzler. To be very effective at coupling to the eye in a non medical situation, well, without cluing in the so called "tangos" too much, you need to match the optics to the entrance pupil of the of the eye. So much for a compact pocket combined dazzler/phaser/ eye blaster blinder for 90$ from China. To have a high "Pk" you need an uncomfortably large lens, and not just a normal collimator. One that will draw attenuation to you. It wont be concealable in a pants pocket.
The myth that Dazzlers are very safe at close range, is just that, a myth, as a few soldiers found out with early dazzlers playing laser "tag" across a truck bed are now on permanent disability. This lead to much Dazzler redesign.
Since we're inhabitants of the third rock from the Sun, Its bright here. Our eye's optic nerve is offset in such a way that its unlikely that an easy irradiation is going to totally destroy vision. At very close range with a tight low power CW beam there is a huge risk of damage, but not a large risk of more then partial disability. Popping the fovea with a low power handheld in the right place is very unlikely, odds are the beam will go into the peripheral vision area. With a determined attacker, you just angered them more. Your a target with a beam trail leading back to you.
Another lesson learned from the Military, Dazzlers carry huge risks of being a beacon to their users. They get used as a last resort before firing, because right next to them sets the "Patrol Leaders Laser Designator" a hot handheld used for directing fire when under cover. That little 30 mW red pointer attracts gun and rocket fire on Smokey battlefields, so its only used "When you really have to use it, or have a tactical overwhelming advantage"
One of the problems of learning laser safety is that you have to calculate for each situation and assign a probability of damage. This is why there are constant laser safety questions on every laser forum and physics/bio forum in
the world. Usually the only way to determine if something laser is really safe/unsafe is to measure it.
So we teach everybody, and for all the right reasons, to assume you are holding the equivalent of a knife or firearm. The rules are set up that way because just like kinetic weapons, high energy chemicals, and nuclear radiation, if your don't have years of math lessons, a good understanding of the physics, and proper measuring tools, you have to assume things are going to be bad if you mishandle the device. That does not mean that all laser irradiations are going to result in total eye failure.
Next up, immediate psychological effects of retinal burns. if you do it to yourself, "Oh Dear Lord I've ruined my vision for life," instant shame and depression, but you don't stop functioning. You get up and move and try to assess the damage. An hour later you may be dealing with immense eye strain for days if not weeks, but to an angry, determined combatant, its not going to stop you immediately. If some one else does it to you, as in my case, its immediate anger "Smite Him, Now, for he has violated my life and made me disabled". Your target then views your device as a weapon. Expect fire headed your way.
I'll disagree with it not being painful. If the beam burns or ablates past the retina, or hits muscle, there are nerves behind the thin layer of light sensing tissue. If you miss the lens and scald the sclara, its GOING to hurt. Mine hurt instantly, yet I have met others who had damage that never found it till they had an eye exam.
For a scared, uneducated, person approaching a checkpoint and nervous from anxiety of living in a combat zone, the random blinking pattern that Dazzler marketers hold so dear as a "Neural Disruption" is somewhat effective. However the tests were first ran on sheep, and remember, sheep have so low a brain update rate, that electric fence pulses have to be below about seven Hz so the sheep don't get "hung up" on the fence. The Human brain is a hell of a lot faster, so the disruption can be defeated after a second or two. However most users go to the warning blink with 50% duty cycle, 1 second rate that is so effective at attracting attention. "Please stop at my checkpoint you civilian fool, I don't want to pull the trigger" is the user attitude. So they use what works, not the weird psychological option. I know from actual tests what was effective and what just caused anger.
Against any teenager and up who has ever gone clubbing and is used to bright stage lighting or seen a camera flash, well.... Flashbang level light bursts are needed and then may not be effective. I've loved very carefully constructed audience scanning laser shows in Canada, in the US with PASS systems, and at a ILDA demo in the US. If beams get too bright, you will duck your head, your eyes will blink closed, and you will avoid the flash. The human aversion mechanism is quite good if not awesome.
Yet there are some situations (Pilots/Drivers who are on task) when you can't avoid the beam, and are dark adapted, which leads me to another point. In daylight/room light, your eye pupil is tiny. A dazzler thus becomes just a bright, blinking light. What good is a defense that is really most useful at night, when attacks are probably mostly in daytime?
Multimode diodes have a horrible beam pattern, Blues at any substantial distance are just going to anger the bad guy. Yes the NOHD of a 1 watt Blue Wicked laser pointer has been measured and published in great detail. However the NOHD is based on a statistical probability of injury, it does not ensure there will be damage.
Let the laser weapons thing rest, I'm not going to tell you how to make an effective one.. That is well known to the worlds militaries, but not pocket sized. Without taking steps well beyond a normal pointer, your "Pk", the probability of a hard kill, is too low to make a laser useful.
If you ask a professional soldier to just blind some one, they will think it through and tell you no. One, they have to care for the opposing combatant who is down, and two, they just made an enemy for life of the whole opposing clan. In some regions, fighting for revenge over an alleged slight that happened seven hundred years ago is the norm, not the exception.
Go take an ALICE course, and realize that most civilian combat is within 21 feet, so unless your sacrificing yourself to save others, closing with your attacker, especially a sick, motivated, deranged one who has already enjoyed the "power trip" that comes from killing, is just plane dumb. Why turn a beacon onto yourself?
Now days, officers in a School Shooting are trained "See Gun, Shoot Gun", and that assisting civilians with firearms are not to be part of their team.
Its not a long stretch to "See laser user, shoot laser user". When Asked what I should do if we disarmed an attacker, I was told, drop the weapon, kick it away, get rid of it, at best put it in a corner or set an upside down trash basket on it. Don't even clear the chamber. Reason being, "See Gun, Shoot Gun", and that even if the civilians had neutralized the attacker, the cops are thinking tactical till the scene is secured their way.
LA County Sheriffs Department has a really good ALICE video on Youtube. I've taken ALICE at work. At my former church we had ALICE plus practice with attacking off duty officers who were role playing. Flying books hitting the attacker in the face are actually a better strategy then engaging from a distance with a low Pk device. Take a good course and find out why. You do have options that might surprise you with common items, especially if your not alone.
Steve
