• cynar@lemmy.world
    link
    fedilink
    English
    arrow-up
    4
    ·
    7 days ago

    Most of the problem with lasers come from focusing them. The eye is incredibly good at it. This means even a small laser pen can reach MW/m^2 ranges by the time it hits the retina.

    IR is a different story (at longer wavelengths). Without the ability to see it, our eye will not attempt to focus on it. Also, our eyes lenses are not particularly transparent to it. 3rd, the ultra short pulses mean that there is no time to focus.

    As for the mosquito, the laser is tuned to a frequency that is strongly absorbed by their wings. Given their size and how delicate their wings are, a tiny amount of energy can cause significant damage. Conversely, the same energy on our eye will just cause a slight amount of heating. The bulk mass of the eye will absorb this fine, with no damage