qutools quED - Unpacking and Installation; Contents of Boxes

10 quED Manual www.qutools.com
To verify the entanglement of down-conversion photons a pair of polarization filters is used.
Both the mirror and the coupler are held in kinematic mounts allowing the fine angular
alignment of the coupling mode, which is defined by the single-mode fiber. The full control over
the orientation and the divergence of the coupling mode is imperative to achieve high coupling
efficiencies of down-conversion photons into single-mode fibers. In either arm the iris
diaphragm (8) with adjustable opening is positioned between the mirror and the polarization
filter. For additional information on the alignment procedure, we refer to sections 3.4.2 and
3.4.3. The fiber-coupled down-conversion photons are detected using passively quenched
silicon avalanche photo diodes hidden in the quCR electronic control unit. The corresponding
single detection rates in both arms and the coincidence count rate are displayed on the counter
panel of this unit. To prevent the escape of laser radiation and to prevent personnel access to
the laser beam during normal operations, the pump assembly is housed in a protective
enclosure. The enclosure can be removed when the operator needs to perform maintenance or
adjustment tasks. This is required for example during full alignment procedure described in
section 3.4.3. The front output aperture of the protective enclosure contains the a long-pass
filter which acts as a beam block for the pump laser. Please verify periodically that this filter is in
place and intact. Otherwise, high power laser radiation can escape the housing and potentially
cause harm or damage.
Unpacking and Installation
Contents of Boxes
When you have received the product, please make sure that the following parts are included:
• Box 1: Optics part
o Aluminum breadboard with source, mirrors, couplers and polarizers in rotating
mount.
o 2 polarization maintaining fibers attached to the couplers. These fibers should
never be unplugged.
o 2 long pass filter caps in front of the couplers.
o alignment plate (only to be installed during a full alignment procedure (see
Figure 8 and section 3.4.3).
o Optical fiber checker
o Cable with with SUB-D9 connectors (to connect down-conversion source with
control unit)