Voigt Geometry Upgrade

switch between out-of-plane and in-plane configuration

For many samples studied with confocal microscopy under magnetic fields, switching between the out-of-plane (Faraday) and in-plane (Voigt) geometry reveals inter-esting differences in behavior. Our new ASH/QE/4CX/CFM sample holder in conjunction with the LT-APO and Voigt objectives respectively allows to study both configurations for one sample within only a few minutes for switching between both setups ex-situ (i.e. after warming up the microscope insert).

In Faraday geometry, the sample is aligned horizontally, such that the vertical magnetic field of a typical single solenoid (such as in the attoDRY1000/1100/2100) is out-of-plane. In this configuration, any of the LT-APO objectives can be used.

In Voigt geometry on the other hand, the PCB that hosts the sample is mounted vertically parallel to the magnetic field onto the quick exchange slider, and the LT-APO is exchanged by the Voigt-IWDO objective. The latter takes care that the optical beam is deflected by 90° into the horizontal direction, and focused onto the sample by the IWDO lens.

The ASH/QE/4CX/CFM sample holder consists of a base plate including a calibrated temperature sensor and a heater, and a quick exchange slider for the sample PCB in two alternative configurations. In addition, it features 8 electrical contacts on the PCB, which is identical for both configurations. Hence, upon switching from Faraday to Voigt, no rebonding of the sample wires is required – only the PCB is unmounted from the Faraday holder, and remounted on the Voigt holder plate. Only the 8 pin connectors for the wiring need to be unplugged and reconnected. Typically, the 8 pins are connected to 4 coaxial wires in our microscope insert, that terminate in a vacuum feedthrough with SMA connectors on the outside.

Both configurations are compatible with the closed loop scanning option (attoFPS based interferometer with 1 nm resolution). In case a scanner is required, the large range scanners ANSxy100/lr and ANSz100/lr yield a combined scan range of 50 µm x 50 µm x 50 µm @ 300 K or 30 µm x 30 µm x 30 µm @ 4 K, and hence allow for horizontal or vertical scans with the same full range of 50 µm in either configuration.

Technical specifications of Voigt-IWDO objective
clear aperture

5.0 mm

numerical aperture (NA)

0.68

working distance (WD) 1.5 mm
Spectal range1

400..1600 nm1

objective type aspheric
compatibility attoCFM I


1
depending on anti-reflective (AR) coating: coating A 400-600 nm | coating B 600-1050 nm | coating C 1050-1600 nm | uncoated

related articles for Voigt geometry upgrade

Art. No.

Voigt-IWDO objective for the attoCFM I

1007621

ASH/QE/4CX/CFM incl. base plate with temperature sensor & heater as well as Faraday slider, Voigt slider and 3 PCB with 8 electrical contacts

1012172

ANSxy100lr/LT large range xy-scanner

1000352

ANSz100lr/LT large range z scanner 1005230