The first attempts at construction by an enthusiast of these objects, often inevitably are aimed at building the simplest buildable device, of which there are countless examples and guides on the net, the laser flashlight is perhaps the most popular construction in the world of those who want to build a laser at a reduced cost.
Often, however, bad advice wins out for construction, see how to boost a laser that cannot be boosted, i.e., how to burn out the diode quickly, how to power it beyond the operating threshold, in short, they almost always teach how to make disasters out of a very delicate diode that is not made to be supercharged and to work at a temperature for which it was not designed.
You start with a diode that you take even from an old burner, try to pull it out, hoping not to deform it, and build an approximate circuit around it and hope it will work for as long as possible.
But this is not the right way, like everyone else I tried it and almost immediately, disappointed with the results, I started thinking about laser flashlights with power supplies specifically for this kind of work, sized correctly, and with a good heatsink (self-made on the lathe), powered in a trouble-free way, with good durability and performance.

Early work with DIY heatsink lathe

Doing a good job of it takes time and attention to detail

And then you work in series!

Then comes the time to put the diode recovered from the burner in its place in the classic Aizix collimator! Gently so as not to ruin anything.

And then finally enjoy the result, after checking that there are NO planes nearby (including helicopters and Sunday aviators) .

Of course over time things have improved a lot from the first steps, and we have arrived at a decidedly professional and well-maintained product, below is the first model and above is the final model that I was able to build. Nothing now distinguishes them from a professional pointer, of course the power though is definitely very high, we are from 250mw to 500mw.

Then over time I practically built all the colors of the rainbow, of varying power.

It was a good exercise but it is a field that I have now completely explored, and from which I have little to learn, which is why we move into uncharted horizons! Box for geeks, but not for fools. Confirmed I am not for sale and do not make any more, this type of device is now a dead field there is nothing to learn.