On the 2nd and 3rd of October, Thomas Hummel visited the University of Iowa hosted by assistant Prof. R. Uppu from the "Quantum Light Control Lab". During this time there were various lab-tours and many discussions. Thomas also gave a guest lecture about the operation and control of SNSPDs.

In our publication, we explored a technique to operate an SNSPD all-optically at cryogenic temperatures. SNSPDs are superconducting single-photon detectors required for quantum optical measurements. Cryogenic operation temperatures are needed for these single photon sensitive devices. Typically, superconducting detectors are operated in a cryostat. Coaxial cables are then used to transmit power and signals between the cryogenic detector and the…

We congratulate Stefan Vorwerk for successfully defending his bachelor thesis about "Characterising laser-written periodic poling in nonlinear waveguides".

Beginning of the week we had our Summer-Event. Most of our group met at the Lippesee and everyone brought some food and snacks. Besides enjoing the nice weather and food, some of us also went swimming. We ended with a competitive match of Ultimate Frisbee, after which everyone was exhausted.

In a short video Nina Lange explains how sum frequency generation works. If you are interested, you can check it out on our YouTube channel.  More information (in German) can be found in this news article from the Institute for Photonic Quantum Systems (PhoQS).

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.