At what intensity or wavelength would the LASER becomes destructive?

Answer 1

your question is actually two
1) intensity: lasers are classified as Class 1, Class 2, Class 3a, Class 3b, Class 4 in terms of their intensity.
class 1 are generall few mW in power but still not to be put directly to the eye
class 2,3a,3b are hazardous to the eye even if reflected properly or diffusely there may go up to 100s of mW
class 4 are the industrial lasers of Watts to Mega watts power
can cut steel weld iron extremely harmful as can cause burning of skin and blinding

2) wavelengths: as u you what we can see is visible light and wavelengths 400-700nm. anything more say upto 15000 nm is infrared. wavelengths of the order below 300nm to 100 nm come under ultraviolet this is dangerous if exposed for long
then few nm wavelength comes x-ray lasers extremely dangerous u know

Answer 2

There are so many types of lasers we can get from different sources. But the CO2 lasers posses high intensity...
See the details below...
Carbon Dioxide (CO2) Lasers (42 companies) Carbon dioxide (CO2) lasers use the energy-state transitions between vibrational and rotational states of CO2 molecules to emit at long IR, about 10 µm, wavelengths. These lasers can maintain continuous and very high levels of power and are typically used in cutting, welding, etching, and marking applications.

Answer 3

Destructive to what, exactly?

Low powered laser pointers are destructive to retinas.

High powered lasers markers/cutters/welders are destructive to large blocks of steel.

Answer 4

a laser is lawyas destructive..
its upon you whether you r using it to destroy bad tissues or good ones...