APOLLO Laser Output Optics
The less cramped output end of the laser contains, from upper right to
upper left:
- The frequency doubler crystal, which converts two 1.064 µm photons
into a single 532 nm photon (green light). The efficiency of the
conversion is sensitive to crystal orientation, so the crystal mounting
block is situated in a motorized one-axis gimbal mount.
- A dichroic passes the residual infrared light to the left (about 1.5 W
of un-converted IR power), turning (almost) all the green light 90° and
out of the hole in the side of the laser box.
- The green light that leaks through the output coupler encounters
a second dichroic, turning the remaining green light (well, 99.9% of it) toward
the bottom of the picture.
- The IR light also passes through the second dichroic, and is
terminated in the beam dump (white bird-house-looking thing).
The fast photodiode is positioned to
intercept the residual green light reflected off the second dichroic.
Amounting to 0.1% of the output pulse, this is still a great deal of light,
and is simultaneously integrated and attenuated for the photodiode by
placing a business card directly over the photodiode entrance. High
tech!
APOLLO Laser Page
APOLLO Apparatus Page
APOLLO Main Page