PDR,
Without going into details that may help the bad guys, I think you need to take a look at the actual beam parameters from a moderate cost 1 watt laser pointer. Your required laser power estimate for damage at higher elevation is off to the high side by a huge factor..
I just ran your numbers thru a professional beam safety program, and if one small beam detail is improved by a factor of 10, the 1 Watt laser has a Nominal Ocular Hazard Distance far longer then your giving it credit for.
Especially if the inadvertent viewer is wearing eye glasses, and if the pointer user has added, or purchased a certain common modification.
However, I'm glad that your attempting the math instead of just repeating the common assumptions and rumors that are out there.
I work with laboratory lasers, and laser display projection systems for a living.
The real answer is to convince the Chinese government to stop the dumping of extremely low cost lasers onto the international market.
These low cost, hand held, lasers are a huge cash cow for Chinese optics companies. Most of which have some fairly shady owners, and have long been dumping optical parts at below market value.
Most of the time they are imported under fraudulent labeling to get around Customs...
As I work with Quality American and European systems, I can assure you these low cost lasers have taken a toll on the income, and sanity of legitimate laser users. Now they are slowly creeping into the cosmetic medical device market, via on-line marketing.
And Pilots, one tip from a laser professional. Avoid a possible secondary effect. Do your best NOT to rub your eyes after an inadvertent laser strike. A bright laser strike may strain muscles in the eye. Then if you drag a dirty hand thru the eye, you run a strong risk of pulling a muscle or irritating the soft tissue.
I got my start in lasers doing laser shows. The low cost lasers pushed many of us who had professional gear, who obtained the required permits, and insurance for outdoor shows out of business. Most of those low cost laser users are totally unaware or ignoring the fact that they need permits for un-terminated laser shows in airspace. Filing the paperwork generates NOTAMs, and there is a lot of math required to ensure safety compliance. That means that the companies who still try to be legal must turn down a lot of potential customers, as there is a delay, and mandatory review period with the local agency.
Most of the time, if the green 532 nm wavelength is blocked, that takes care of 90% of the offenders. However when you start getting into multiple wavelength blocking filters, the optical transmission of non-laser light goes way down. If you block the needed red band, you loose viewing much of the aviation standard red and green lighting.
I've been reading PPRUNE as a outsider for years, sorry that my first post has to be on such a disgusting topic.
Sim