All-Oxide Compact Tunable Laser

• Applicants: Professor Dr. Lambert Alff; Professor Dr. Sascha Preu
• Subject Area: Synthesis and Properties of Functional Materials ; Communication Technology and Networks, High-Frequency Technology and Photonic Systems, Signal Processing and Machine Learning for Information Technology
• Term: since 2024
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 546857785

We propose an all-oxide, compact laser concept with intra-cavity tuning at GHz rates. The vertical cavity surface emitting laser (VCSEL) will be composed of a layer sequence of perovskites and oxides that are grown by pulsed laser deposition (PLD). The structure will combine several types of functional layers: Barium (Strontium) titanate as electro-optic material with extremely high electro-optic coefficient for tuning the optical cavity length. It will be epitaxially integrated with optically transparent Strontium-Vanadium-Molybdate electrodes that offer excellent conductivity close to that of metals. The intra-cavity integrated electrodes will be used for applying the tuning voltage to the electro-optic material. The laser-active medium will be Ti:Sapphire, also grown by pulsed laser deposition. The PLD-grown materials will be combined with PLD or PECVD grown Bragg mirrors comprising the laser cavity. Due to the short cavity size, the laser will offer an extreme mode-hop free tuning range. It will be a first demonstration example of a revolutionary material platform based on oxide materials with applications in electronics and optics or mixed optic-electronic circuits as well as potential integration into modern photonic or electronic integrated circuits. The project will be carried out through a collaboration between electrical engineering and materials science to develop the laser concept from the material to the final innovative compact VCSEL.

• DFG Programme: Research Grants