On-Chip Multidimensional Control of Twisted Moiré Photonic Crystal for Adaptive Sensing and Imaging

Abstract Moiré photonic structures permit the engineering of optical band structures and light-matter interactions, offering new opportunities in photonics and optoelectronics, paving the way for new nanophotonic applications, such as ultra-low threshold lasing and versatile nonlinear and quantum light sources. Until now, however, the lack of in situ tunability has limited the potential of these structures. For example, the lack of control of the twist angle poses challenges for high-resolution material spectroscopy and the development of new applications that require moiré optical properties. In this paper we present a MEMS-integrated twisted moiré photonic-crystal sensor with tunable interlayer distance and twist angle. The MEMS actuators modulate the wavelength and polarization resonances of the photonic crystal sensor via a twist- and gap-tuned moiré scattering effect. Using a reconstruction algorithm, this chip-based sensor can be used to simultaneously resolve the spectrum and polarization state of a wide-band signal in the telecom range and the full Poincaré sphere. We also demonstrate hyperspectral and hyperpolarimetric imaging using this single sensor. Our research illustrates some of the remarkable applications of multidimensional control of degrees of freedom in twisted moiré photonic platforms and establishes a scalable pathway towards creating comprehensive flat-optics devices suitable for versatile light manipulation and information processing.