PAGE 144
attoCFM IV
combined free-beam and fiber-based confocal microscope for transmission
Transmission experiments in confocal microscopy sometimes also
require filtering and shaping of the optical beam, and hence free-beam
access instead of purely fiber-based can have quite some advantages in
terms of flexibility. this setup allows for at least either the excitation or the detection
to be free-beam. This provides the user with all the flexibility of the
external optics head just like in case of the attoCFM I for one channel
(plus potential reflection measurements).
This instrument literally consists of a ‚conventional‘ attoCFM I, which
has a free-beam based channel with any of our apochromatic objec-
tives above the sample, and a fiber-based channel from below just like
in the attoCFM III. So, despite fitting into any of our toploading cryo-
stats, which usually features only 1 top and no side or bottom windows, At the same time, there are 3 degrees of freedom for the sample (xy
translation under the fixed LT-APO objective as well as focussing),
and another 3 degrees of freedom in xyz to position the fiber-based
objective underneath the sample. All positioners are usually equipped
with a /RES encoder for closed loop control, and there is an additional
scanner for the sample in xy direction.
1
6
8
2
7
01 attoCFM I external optics head
3
02 vacuum window & fiber feedthrough
03 microscope insert and cryogenic microscope module
5
4
04 attoDRY1100 cryostat (optional)
05 superconducting magnet (optional)
06 cryogenic apochromatic free-beam objective (LT-APO)
07 sample with xyz coarse positioners & scanners
08 fiber-based aspheric objective with xyz coarse
positioners & scanners