Confocal Microscopy (CFM) | Fiber-Based Setup
fundamentals
While the free-beam based attoCFM I offers a maximum amount of flex-
ibility (see previous page and page 126), its fiber-based counterparts
attoCFM II and attoCFM III offer ultimate long-term stability onto the
sample, and back up to the detector. The accessible wavelength range
onto the sample, and back up to the detector. The accessible wavelength
range for both the excitation and detection is thus limited by the range
of the single mode fiber used.
attoCFM III
attoCFM II
The key feature of this system is its unprecedented stability allowing
long-term investigations over many weeks without readjustmen. This
can become crucial when working with single photon emitters (e.g.
quantum dots), and when tuning several external parameters (like
magnetic field or gate voltage) over long periods.
A single-mode fiber is used for both excitation as well as detection,
sharing the optical path all the way from the fiber coupler inside the la-
ser detector module (LDM600), down to the low temperature objective,
This is the system of choice for customers who are working with trans-
parent samples in transmission mode. Here, the confocal microscope
essentially consists of two separate attoCFM II: one single-mode fiber
for excitation, and one separate fiber and low temperature objective
for detection. Using two different single mode fibers for the two optical
paths enables access to a larger and more flexibel wavelength range
than with the attoCFM II.
4
CFM II
4
5
CFM III
5
1
1
ASC400
ASC400
ASC400
3
3
2
S
Y
S
Y
6
X
Z
Y
X
Z
Y
X
Z
2
X
Z
7
8
6
7
8
9
9
01 ASC400 scan controller 04 Single mode fiber 07 Sampler
02 LDM600 laser source* 05 Vacuum feedthrough fiber 08 xyz positioning (optional scanner)
03 LDM600 detector 06 Low temperature objective 09 Cryostat
attoMICROSCOPY
Sophisticated Tools for Science