Greetings.

If all the lasers below emit the same optical output power, the most dangerous one to retina damage is the purple because is barely perceived + carries the highest energy due the highest frequency. Is that correct ?

Being the eyes poorly sensitivity to purple, eye damage is easier to happen for that color emission, do protective goggles have to be much better than for other colors ?. Is that right ?

If proper purple-blocking goggles mask/attenuate the color; locating an aimed target may be very difficult to see. Is that right ?

Is there such a thing as a coaxial dual color laser -say simultaneous pointer green and high powered purple- that with proper protection goggles blocks the dangerous and allows seeing the aiming spot ? Like the green only to show where the purple is aiming ?

I have several salvaged optical blocks from DVD/CD writers that use a prism to focus to the same spot. Would that be an alternative to "coaxial" beams ?

6 minutes ago, Externet said:

Is there such a thing as a coaxial dual color laser -say simultaneous pointer green and high powered purple

Yes. There are lasers that use frequency-doubling crystals, such as a 1064 nm (IR) pump laser that gives 532 nm (green) light. (Usually the 1064 is filtered out, but cheap ones had poor filters and were dangerous because there’s no blink reflex, and doubling is not efficient so there was a lot of that light.)

Thanks. Looking for a violet laser and a red in one package, saw this as 'burner' but mentions 'class 1' Can it be class 1 if is a 'writer' ?

Do you know which device uses a violet burner laser diode plus other in one package ?

This is from memory, so buyer beware, but IIRC while laser class depends on power, it also depends on packaging. A class 1 laser product means that it’s eye-safe, but that can be because it’s completely enclosed. The laser itself could be a higher classification. e.g. when you open the box it’s class 3 or 4. We used point this out when we had safety inquiries. We had 3b and 4 lasers, but they were in boxes with only a fiber output, and that fiber went to another enclosure, so no eye protection was needed. (and no interlocks turning them off when you opened the lab door)

The blu-ray burner writer might use one color to write data and lower power and possibly different color for playback.