Quanta can not only be used to calculate, but also to measure and communicate. This combination will enable a wide range of products to be created in the information and communication technology sector and on the sensor market in the coming years. Manufacturers need highly specialized equipment and processes to make use of the fundamental principles of quantum mechanics. Fraunhofer IZM has now planned one of these.

Quantum objects are only a few nanometers in size, but they act in unique ways: For example, they have neither an exact position nor a precise direction of movement. Particles that are far apart can even be entangled with each other. Based on these phenomena, researchers around the world are developing quantum technologies that open up unparalleled potential for applied research in various industries. To help shape this revolution, the Fraunhofer-Gesellschaft commissioned the first quantum computer in Germany at the beginning of the year.

The next step is the Berlin QuantumPackagingLab, which will be available from mid-2022 as a contact point for the development of reliable packaging approaches for quantum photonics. The researchers there are trying to use glass as a transparent substrate and carrier for future photonic circuits. They also want to extend existing waveguide technologies to the visible and near-infrared range, the so-called VIS-NIR spectrum. To do this, they are using panel level integration techniques that were developed for electrical circuit boards. In order to tackle the assembly techniques, packages and system integration for photonic quantum technologies, a new infrastructure is being set up in a total of four laboratories at the Fraunhofer Institute for Reliability and Microintegration IZM. The following five large-scale facilities are of particular importance:

• Scanning Nearfield Optical Microscope (SNOM): The SNOM in the optical measurement laboratory uses optical spectroscopy to examine the surfaces of nanophotonic components. The core of the process is that laser light with a minimum diameter, smaller than that of a waveguide, is focused in the immediate vicinity of the sample. In addition, the so-called evanescent field, which is created when a light wave decays optically at interfaces, enables highly reliable measurements to be carried out.
• Waveguide coupler: The automated large-scale system uses an integrated camera as well as search and optimization algorithms to simultaneously couple several waveguides to a fibre array. The coupled light is detected at the output side of the waveguide.
• 3D glass printer: It structures glass using ultrashort light pulses. In a downstream process step, glass surfaces can be etched and thus modified. The device is aimed in particular at laser direct writing, i.e. the direct lasering of waveguides and photonic structures such as diffraction gratings into glass. Other functions include the drilling of micro-holes in glass and welding, in which the glass is only heated locally, making it possible to create hermetic and transparent glass-glass welded joints.
• Micro ultra-high vacuum bonder: With this system, the researchers plan to carry out laser soldering and other hermetic glass bonding processes under vacuum conditions. The highly focused laser radiation is absorbed by the glass solder. This causes it to heat up above the melting point of the solder, which leads to the glass surfaces being joined.
• Ultra-high vacuum evaporation system: The ultra-high vacuum evaporation system can be used to evaporate metallic coatings onto glass surfaces with a thickness of a few nanometers and a precision of one nanometer. The processes are used to produce semi-transparent, metal-coated mirrors, and the metallic surfaces themselves can also become conductors of plasmons.

Fraunhofer IZM is now looking for research partners with whom it can develop application-oriented system integration, in particular assembly technology and packaging, for the fields of quantum communication and sensor technology.
The QuantumPackagingLab is being funded by the state of Berlin with a total of 3,392,000 euros as part of ERDF co-financing.