Shutter in 2-P scope

[Quoc Thang Nguyen-2]

*****
To join, leave or search the confocal microscopy listserv, go to:
http://lists.umn.edu/cgi-bin/wa?A0=confocalmicroscopy
*****

Dear all,

I would like to get an opinion about mechanical shutters in two-photon scopes.

1) Are they required for safety reason even if there is a Pockels cell in the beam path and
the ultrafast laser has an internal shutter?

2) Also does anyone know of a good shutter that can tolerate at least 3 W of continuous
power?

3) Do you place a beam dump to catch any reflection when the shutter is closed?


Thanks in advance.

[Pascal Weber]

*****
To join, leave or search the confocal microscopy listserv, go to:
http://lists.umn.edu/cgi-bin/wa?A0=confocalmicroscopy
*****

It is always good to have more security in the light path. The shutter can
withstand the power of the radius. They are metal but remember that even if
it is black, the reflections are dangerous.The reason why you may have a
protection around the beam path. Safety glasses will protect you as
secondary rays. To be protected I stick a black sheet on the thermostated
boxe around the microscope (low price). Picture on request

[Craig Brideau]

*****
To join, leave or search the confocal microscopy listserv, go to:
http://lists.umn.edu/cgi-bin/wa?A0=confocalmicroscopy
*****

A mechanical shutter is always a good idea.  Pockel cells are electronically
controlled, so a controller glitch or crash could theoretically cause it to
be stuck 'open'.  The better mechanically shutters are designed to fail in
the closed position, so if power to the shutter is cut it snaps shut
automatically.  Finally, while it does a good job, a PC cannot completely
absolutely block a laser the way a physical shutter can.

Craig


On Tue, Oct 18, 2011 at 12:10 AM, Pascal Weber <[hidden email]>wrote:

> *****
> To join, leave or search the confocal microscopy listserv, go to:
> http://lists.umn.edu/cgi-bin/wa?A0=confocalmicroscopy
> *****
>
> It is always good to have more security in the light path. The shutter can
> withstand the power of the radius. They are metal but remember that even if
> it is black, the reflections are dangerous.The reason why you may have a
> protection around the beam path. Safety glasses will protect you as
> secondary rays. To be protected I stick a black sheet on the thermostated
> boxe around the microscope (low price). Picture on request
>