Precision picosecond laser for the microstructuring of materials

• Subject Area: Electrical Engineering and Information Technology
• Term: Funded in 2023
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 516836168

The subject of this proposal is the procurement of a system ("precision picosecond laser") for high-resolution and material-conserving structuring and surface treatment of a wide variety of materials for research into new sensor and sensor integration concepts. The main focus is on 1st and 2nd-generation spin-based quantum sensors and their integration. More specifically, the system will initially primarily be used for the research and design of miniaturized and scalable nuclear magnetic resonance (NMR) and electron spin resonance (EPR) sensors, as well as quantum sensors based on defects in semiconductor materials such as diamond and silicon carbide (SiC). Such sensors usually require a resonant radio frequency (RF) magnetic field (B1 field) of high spatial homogeneity to control the spin qubits. In addition, for optimum performance, this B1 field must be adjustable in its amplitude and phase with high temporal resolution. One possibility to design such sensors in a scalable way and with excellent performance is to use chip-integrated electronics – so-called NMR- or EPR-on-a-chip transceivers – for the required excitation and readout electronics. The required field generating structures (coils or resonators) can either be co-integrated on the chips or realized off-chip. Planar on-chip coils offer minimal parasitic capacitances and lead resistances but are limited in the achievable homogeneity of the B1 field due to their restricted (planar) geometry. Here, the requested device offers the possibility to create holes in the center of the on-chip coils, which makes it possible to significantly increase the usable sensitive area of the on-chip coil and, at the same time, to improve the achievable homogeneity significantly. In the current state-of-the-art, high-frequency printed circuit boards (PCBs) on special substrates are often used to realize off-chip coils and resonators. Here, thanks to its high spatial resolution, the requested device enables the design of miniaturized and highly efficient RF and microwave structures. Here, similar to on-chip coils, the laser can be used to create holes in the structures to increase the usable sensitive volume and the achievable homogeneity. At lower frequencies, it is also possible to use flexible substrates, which enable 3D coils with high homogeneity of the B1 field by rolling or folding the substrate. Here, the requested system is ideally suited both for structuring the metallization of such flex substrates and for structuring the substrates themselves. In addition to the aforementioned applications, the requested laser system will also be used for the spatially selective activation of non-conductive substrates such as polymers to enable their spatially selective metalization.

• DFG Programme: Major Research Instrumentation
• Major Instrumentation: Präzisions-Pikosekunden-Laser für die Mikromaterialbearbeitung
• Instrumentation Group: 5700 Festkörper-Laser
• Applicant Institution: Universität Stuttgart
• Leader: Professor Dr. Jens Anders