In our paper, we demonstrate the coldest spontaneous parametric down-conversion (SPDC) experiment that was done so far. We show that SPDC in nonlinear waveguides, which is typically performed under ambient conditions, remains functional when it is operated at about 4 K. We investigate the source performance metrics and the spectral properties of our SPDC source. Our results indicate that cryogenics principally affect the modes which the SPDC…
We congratulate Johanna Biendl who has successfully completed her master's studies titled "3D Lithography of Micro-Structured Etalon Arrays for Single-Photon Spectrometry".
Students from the MINT-EC-Camps visited the university of Paderborn, and the MQO-lab. The focus was on all the lasers being used, and why we need them.
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From November 1st till November 5th was the digital QIM VI conference 2021. The MQO group contributed with a talk from Timon Schapeler. His presentation can be found under the following link.
In our new paper, we demonstrate the integration of amorphous tungsten silicide superconducting nanowire single-photon detectors on titanium in-diffused lithium niobate waveguides. We show proof-of-principle detection of evanescently coupled photons of 1550 nm wavelength using bidirectional waveguide coupling for two orthogonal polarization directions. We investigate the internal detection efficiency as well as detector absorption using…
We congratulate Lucas Alonso who has successfully defended his bachelor thesis titled "Quantum detector tomography of an 8-bin time multiplexed detector".
On the 7th of August the group went on a trip to Westenholz to play some Swingolf. On several different courses, some of them longer than 100 meters, each member of the MQO-Group could demonstrate his or her skills. Even though a few balls got lost in the bushes, it was a lot of fun and we had some really good weather. In the afternoon we then visited Delbrück with its leaning church tower to eat some delicious Pizza.
We congratulate Niki Suckau who has successfully defended his bachelor thesis titled "Comparing Laser-Written and Mask Lithography for Periodic Poling of Nonlinear Waveguides".
From June 21st till June 25th was the digital CLEO Europe conference 2021. The MQO group contributed with talks from Nina Lange and Frederik Thiele and a poster from Maximilian Protte. Their presentations can be found under the following link.
From May 10th till May 14th was the digital CLEO conference USA 2021. The MQO group contributed with a talk from Timon Schapeler. His presentation can be found under the following link.
In our paper we demonstrate and verify quantum detector tomography of a superconducting nanowire single-photon detector (SNSPD) in a multiplexing scheme which permits measurement of up to 71 000 photons per input pulse.
We congratulate Nina Amelie Lange who has successfully completed her master's studies titled "Towards Cryogenic Parametric Down-Conversion in Lithium Niobate Waveguides".