02- Light-path engineering in disordered waveguiding systems

Integrated photonic devices interconnected by waveguides allow realizing optical systems in which the interaction between propagating optical modes and matter can be conveniently engineered by joint numerical design and experimental implementation. Reliable nanofabrication methods enable experimentally scanning relevant parameter spaces and provide devices with high reproducibility. The dense integration of different optical elements into complete systems allows for creating devices with compact footprint. While traditionally highly optimized functional optical elements have been used for system design, disordered optical elements add additional photonic degrees of freedom to overcome limitations in optical bandwidth, sensitivity and compactness. These tuning knobs are of interest for applications both in classical optics, as well as for devices that operate in the single photon regime.

Having previously implemented both efficient experimental approaches for the physical realization of disordered devices and combined numerical and theoretical approaches for the theoretical study of disordered components, in this project we will study fundamental properties of light with functional devices. We will move beyond classical optical devices to study single photon propagation in disordered waveguide structures. Disordered media will be analyzed for non-classical multi-path interference as well as for single photon scattering in randomized systems. Broadband operation in the classical regime will be complemented with broadband single photon detectors based on superconducting nanowires. By exploiting scalable fabrication approaches both for photonic components and active single photon elements, we will focus on multi-detector architectures to harness disorder for imaging applications, as well as to exploit random speckle patterns to increase spatial resolution of fiber-based waveform transformations. By combining theoretical analysis/simulation and experimental verification a new generation of planar single photon devices will be created that harvest functionality from disordered media.

Contributors

References

• Design study of random spectrometers for applications at optical frequencies, P. Varytis, D. Huynh, W. Hartmann, W. Pernice, and K. Busch, Optics Letters 43, 3180-3183 (2018).
• Low-loss fiber-to-chip couplers with ultrawide optical bandwidth, H. Gehring, M. Blaicher, W. Hartmann, P. Varytis, K. Busch, M. Wegener, W. Pernice, APL Photonics 4, 010801-010807 (2019).