In our paper, we demonstrate the generation of degenerate photon pairs from spontaneous parametric down-conversion (SPDC) in titanium-indiffused waveguides in lithium niobate at cryogenic temperatures. We characterize the indistinguishability of our photons with a Hong-Ou-Mandel interference measurement. We show sufficient understanding and control of the cryogenic nonlinear process, which has wider implications when combining quasi-phase-matched…

Last week we visited Libori as a group. We enjoyed some nice food and it was a good opportunity to chat.

We congratulate Maximilian Protte who successfully defended his PhD thesis titled "Building Blocks for Integrated Homodyne Detection with Superconducting Nanowire Single-Photon Detectors" and was awarded the "Dr. rer. nat." degree by the Faculty of Science at Paderborn University.

Our group members Nina Lange and Timon Schapeler visited the Quantum 2.0 conference in Denver, Colorado this year. As the name suggests, the conference covered toptics such as quantum communication networks, quantum sensors, quantum computing, and more. Between the sessions and in the conference breaks a lot of fruitful conversations were held. Nina presented a poster on: "Cryogenic Degenerate Spontaneous Parametric Down-Conversion" Timon…

The week before the Quantum 2.0 Conference in Denver two members of the MQO group (Nina Lange and Timon Schapeler) visited the National Institute of Standards and Technology (NIST) in Boulder, Colorado, USA. They were shown their laboratories and had great discussions about superconducting detector technology.

Our group member Frederik Thiele visited the Conference on Lasers and Electro-Optics in San-José this year. The conferences topics ranged from recent investigations in integrated optics to quantum optical advancements. During the sessions and in the conference breaks a lot of fruitful conversations were held. Frederik presented a talk on: All-Optical Biasing and Readout of a Superconducting Single-Photon Detector.

As a member of the SFB project TRR 142, Nina takes part in the coaching program for young female researchers. Together with six colleagues the kick-off took place on World Quantum Day, when the young scientists could discuss next steps for their career and develop some new ideas. The kick-off workshop will be followed by individual coaching sessions with business coach Uta Stiene, which will enable further personal development.

After seven years of being in the group, we finally had to say goodbye to Jan Philipp. Last Friday was his last day, that is why we met in the afternoon to have some food together, play games and reminisce by a presentation Jan Philipp prepared. Thanks for all your work, you were a big part of our group!

One of our PhD students Frederik Thiele travelled to Bristol in the UK and visited the Bristol Quantum Information Technology Workshop. He presented a poster and gave a presentation on "All optical operation of a superconducting photonic interface". Fruitful discussions and new ideas were exchanged during the workshop and meeting in Bristol. We thank the organizers for a great workshop and their hospitality.

Last Friday on April 14th was the World Quantum Day, where the general public had the opportunity to visit Paderborn University and get insight into our optics labs, as well as the cleanroom. Members of our group, along other members of the institute gave tours. Some more infos about the World Quantum Day can be found in this article on the PhoQS website.

Last week we had our group reflexion meeting. While having breakfast together, we discussed about good scientific practice, future plans and more.  In the evening we met at the Trampoline Park in Paderborn and had a lot of fun. After an hour of jumping around and doing the climbing parcours we were exhausted and filled up our energy with some burgers and fries.

Parts of our group helped to plant trees for the Campus Wald project of our University.

Seven members of our group went to the Spring Meeting of the Atomic, Molecular, Quantum Optics and Photonics Section of the German Physical Society (DPG SAMOP) in Hannover. The conference was held at the Leibniz University from March 5th to March 10th. We presented the following contributions: Timon Schapeler - Quantum characterization of superconducting detectors (Talk) Johanna Biendl - 3D lithography for single-photon level spectroscopy…

We congratulate Markus Brieden for successfully defending his bachelor thesis titled "The characterisation of a single-photon grating spectrometer".

On Tuesday evening most of the group met for our christmas party, we had a great time!  Everyone brought food, we had warm soup and Punsch, cake and more. Together we played a crime game and successfully found the "culprit".