i maybe wrong, i only have wikipedia to go by, but i believe for the
IR laser in the kinect to be eye-safe, it needs to be in order not to
burn your retina.
the reason its eye-safe is that the particular IR wavelength is
heavily attenuated by water and similar liquids like the fluid in your
eye.
I wonder if the defraction grating can be swapped to a different
laser,
quoted from wikipedia
"Certain infrared lasers with wavelengths beyond about 1.4 micrometres
are often referred to as being "eye-safe". This is because the
intrinsic molecular vibrations of water molecules very strongly absorb
light in this part of the spectrum, and thus a laser beam at these
wavelengths is attenuated so completely as it passes through the eye's
cornea that no light remains to be focused by the lens onto the
retina."