Selected Application
Resonant spectroscopy on a single quantum dot with the attoCFM I
Spectroscopy of semiconductor quantum dots (QDs) under resonant optical laser excitation and of other single photon emitters, such as vacancy-centers often yields more
information about the emitters than more ubiquitous non-resonant excitation. However,
it is a technically challenging measurement to perform. The difficulty lies within the separation of the excitation laser photons from the re-emitted and scattered photons. One
way in which this can be achieved is by means of polarization suppression: in a geometry
where the scattered laser photons have a well-defined polarization, they can be filtered
from the detected signal facilitating the detection of resonance fluorescence (RF) of a
single quantum dot or any other quantum emitter.
The attoCFM I can be upgraded with a resonant fluorescence package (see left page),
which features an apochromatic performance that permits alignment free switching
between off resonant PL measurements and RF. This feature is fully enabled by our novel
cryogenic compatible apochromatic objectives designed to hold the focus plane at the
same position on the sample independently from the photon wavelength.
This for the first time combines the use of high precision rotators within the flexible
beam-management confocal head attoCFM I. It provides extinction ratios of 107, a factor
just 10 away from world record in research labs [1] while allowing an unprecedented flexibility of use.
The top figure shows the resonance fluorescence of a quantum dot measured with the
attoCFM I equipped with the Polarization Extinction Option and a narrow band tunable
laser. In order to resolve the Mollow triplet, the emission is filtered through a high resolution spectrometer. Here, the extinction ratio exceeds 106, using the low temperature
near infrared apochromatic objective LT-APO\NIR.
The bottom figure shows the extinction ratio of the Polarization Extinction option for
the attoCFM I as a function of the rotation angle of the inbuilt piezo rotator equipped
with a quarter wave plate. In an angular region of 30 m° an extinction of more than 106
can be reached with a tunable narrow band diode laser (<1 pm line width).
[1] A.V. Kuhlmann et al., Review of Scientific Instruments 84, 073905 (2013).
(Measurement and data by E. Kammann1, S.H. E. Müller1, K. Puschkarsky2, M. Hauck2, S. Beavan2, A. Högele2, and K. Karrai1,
1
attocube systems AG, Munich, Germany, 2Ludwig Maximilian Universität, Munich, Germany)
attoDRY LAB
Dry Measurement Systems
attoCFM I+
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