LUMENIS VersaPulse PowerSuite - 3.2.2 YAG Channel Alignment; 3.2.2.1 Making Test Burns

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3.2.2 YAG Channel Alignment
When properly adjusted the YAG channel will meet each of the following three criteria.
• The cavity HR will be positioned to direct the YAG output to the center of the first relay mir-
ror, and the cavity OC will be positioned to provide maximum power for that HR position.
• The first relay mirror and second (plano) relay mirror will direct the YAG energy off the two
folding mirrors so that it is centered through the wedge optic apertures and centered into
the proximal end of the fiber.
The adjustment procedure for a single channel follows. The procedure is a complete check out and alignment
for a single channel. The procedure is meant to be done in the order given, from beginning to end.
It may often be appropriate to do less than the complete adjustment, but in such a case the field service
engineer must consider the possible effect of doing only a portion, i.e., the adjustment may have an effect on
some other portion of the alignment. As an example, if a single channel is only slightly out of center at the
fiber port, it can usually be corrected by simply adjusting the first relay mirror (using the fiber detector signal)
and then confirming the adjustment using a test fiber burn.
When replacing a damaged optic, it should not be necessary to do the entire procedure. Try to bring the
system back into alignment by adjusting the optic that was replaced.
3.2.2.1 Making Test Burns
(Refer to Fig 3.2 and 3.3) Checking out and aligning the YAG channels requires making burns on photopaper
to check alignment. The Alignment Aperture and Cross Hair Aperture are two special purpose tools used
when making burns.
In general, when making burns, lower pulse energies and fewer total pulses are better. As the total energy of
the burn increases, the footprint becomes "blurred". In some cases it will be necessary to get a "multiplexed
footprint", i.e., the paper is burned by more than one channel, allowing the YAG beam positions to be
compared. In other cases a single channel burn will be required. The service engineer can select the channels
to be fired, a lamp current and a pulse rate at the service screens. Setting a lower pulse rate allows the
footswitch to be operated to obtain just a single pulse from a channel, or from each selected channel.
The alignment aperture is used to center the YAG beam(s) in front of the second wedge optic. It holds a piece
of burn paper (covered on both sides with plastic to contain splatter). A good burn will fall inside the aperture
(the aperture will not clip the beam). The tool is keyed with two small posts that fit into holes on the face of the
second wedge optic housing block. To use the aperture, slide burn paper and plastic in through the side, then
insert it on the second wedge optic housing.