The attoCFM IIxs is a compact confocal microscope based on one single- mode fiber. The one-of-a-kind combination of materials allows absolutely stable measurements at low temperature over weeks on a single quantum object, even when refilling the bath cryostat with liquid helium. Furthermore, combining the attoCFM IIxs with cryogen-free cooling solutions is easily possible, opening up new possibilities in cryogenic long-term investigations while considerably reducing operational costs.
Objectives with a working distance of up to 3 mm or with a numerical aperture of up to 0.68 are available. An overview of the 2 different available objectives is listed in the table in the ‘low temperature confocal objectives’ section.
An increase of the numerical aperture by a hemispherical sapphire lens (solid immersion lens) is possible, leading to a resolution of 150 .. 300 nm (with red laser light illumination).
Principle - A laser beam is coupled into one arm of a single mode optical fiber coupler. The fiber end of the second arm is placed in a ceramic ferrule to guarantee an accurate position of the fiber in the objective axis. This single mode fiber illuminates the sample and plays the role of the blocking pinhole aperture when collecting the scattered light from the sample.
Fields of Application
PRODUCT KEY FEATURES
- miniaturized microscope head
- interferometric or capacitive encoders for closed loop scanning
- designed for highest stability
- optimized for minimal light loss
- large coarse positioning range at low temperatures
- ultra compact version for 1 inch (25.4 mm) setups available
- fits standard cryogenic and magnet sample spaces
- minimized drifts enable long-term measurements
- excellent stability in high magnetic fields
- highest measurement sensitivity
- access to a large area on the sample surface
- solid state physics and quantum dot optics
- fluorescence observation
- highly stable long term experiments on single quantum dots
- biological and medical research on tissue samples in cytological and neurological applications
- fast 3D-imaging
COMPATIBLE COOLING SYSTEMS
- Quantum Design PPMS, see compatibility chart
- any cryostat with bore size >= 1" (25.4 mm)
PPMS Compatibility Chart
quick overview of compatibilities between
Measurement of electronic state hybridisation under magnetic field at cryogenic temperatures.
Photoluminescence intensity of a triply charged InAs quantum dot vs. magnetic field (red corresponds to high intensity), recorded at cryogenic temperature using the attoCFM II. Instead of showing a diamagnetic shift, the triplet state suddenly couples to the 2D electron gas as can be understood from the 1/B periodicity.
|(K. Karrai et. al., ‘Hybridization of electronic states in quantum dots through photon emission‘, Nature (2004) 427, 135)|
Photocurrent Measurements on Graphene Devices using the Fiber based attoCFM
Spatially resolved photocurrent measurements on a graphene field-effect device in the QHE regime are presented to study the distribution of Landau levels and its relation with macroscopic transport characteristics . The exceptional stability and the ease of use of the attoCFM microscope greatly facilitated these measurements and allowed for measuring working devices in magnetic fields from -9 to +9 T.
| G. Nazin, Y. Zhang, L. Zhang, E. Sutter, P. Sutter, Nature Physics 6, 870–874 (2010)|
Tab 5 Rechts