Work Packages

The QUICK3 project is structured in different interconnected work packages (WPs), some of which (WP 1-5) focus on the quantum payload and others on the satellite system (WP 6-8). The mission management is part of WP 9. In the initial project phase (pre-launch), the satellite system work packages assist with the space qualification on the individual component level and design the satellite bus. In the operational phase (post-launch), the satellite system work packages operate, maintain, and control the satellite in orbit. 

The quantum payload work packages initially develop the individual components and sub-systems for the payload, which are integrated together on the satellite. This includes the excitation laser system, the quantum light source, and the quantum interferometer. In the second project phase (post-launch) the quantum payload work packages focus on quantum memory experiments, where the coupling to vapor-based frequency references is explored, as well as concepts for an interface to quantum memories is developed. 

Work package 1: Seed laser system

The seed laser system is responsible for exciting the fluorescent defect in the hexagonal boron nitride (hBN) crystal lattice. While developing a space proofed laser is expensive and cumbersome, we take the new space approach where we test different promising laser systems under space conditions and select a suitable laser that can operate in space. This not only includes the laser itself, but also the control electronics required to operate the laser. At a later stage, we want to be able to modulate the laser intensity for on-demand excitation of the quantum emitter. 

Work package 2: Integrated quantum light source

The integrated quantum light source is the heart of the quantum payload. The transition wavelength of the hBN emitter must be compatible with the laser system: the laser needs a higher photon energy than the energy difference between ground and excited state. But the laser must still fall into the absorption band of the emitter for an efficient excitation. The quantum emitter shall be directly interfaced with the quantum interferometer in WP 3 to reduce the footprint of the integrated quantum light source. 

Work package 3: Quantum interferometer

The quantum interferometer is based on a laser-written waveguide in glass which allows us to write arbitrary waveguiding structures, including our multipath interferometer with which we can probe extended quantum theories in microgravity. With the waveguide we can also implement direction couplers (eg 50:50 beam splitters) to measure the second-order correlation function of our photon source and thereby verify that the photon source emits true single photons. 

Work package 4: Quantum memory concepts

When the emitter is coupled to high-Q resonators, we can funnel the emission into the resonant wavelength and thereby strongly enhance the spectral brightness of the photon source. This provides a promising route for locking the emitter to narrowband atomic transitions of alkali-metal vapors in gas cells. The interaction between the single photons and the vapor can provide a feedback signal for the locking loop. With a better understanding of this interaction, we want to develop a direct interface to quantum memories that do not require frequency conversion between the photon source and the quantum memory. 

Work package 5: Optical integration

Once all individual sub-systems have been developed and qualified, all components need to be integrated together to form the quantum payload. The optical interface between components (seed laser, integrated quantum light source, and commercial single photon detectors) is realized by optical single-mode fibers. 

Work package 6: System design

The interfaces between the commercial 3U CubeSat and the quantum payload, their intrinsic interfaces, as well as with the payload controller are designed in WP 6. This includes thermal, mechanical, and electronical aspects. 

Work package 7: Assembly, Integration and Verification (AIV)

All individual components, as well as the final flight module need to be qualified for use in space environments. Our verification experiments include mechanical shock and vibration tests, irradiation with gamma-rays, as well as thermal-vacuum cycling. 

Work package 8: Mission control and operations

After the satellite launch in 2024, the satellite needs to be operated and controlled from the ground. This includes adjusting experimental parameters as well as the download of the experimental data. 

Work package 9: Management and communication

There is also a dedicated work package concerned with the management of the entire project as well as ensuring the scientific communication between the partners, associated partners, contractors, as well as the scientific community.