Date Published: July 2024
In the lab of Amit Ashok, professor of optical sciences, researchers are pushing the boundaries of exoplanet discovery with quantum optics. In a new study, the team investigates whether current coronagraph designs—devices used to block out light from a star in order to see orbiting planets—are the best possible tools for finding and characterizing exoplanets. The team goes into detail on the project in the publication, "Achieving Quantum Limits of Exoplanet Detection and Localization" and the more recent publication, "Experimental Demonstration of a Quantum-Optimal Coronagraph Using Spatial Mode Sorters." By applying quantum information techniques, they found that ideal coronagraphs, which eliminate only specific optical modes, may offer a significant improvement in detecting and localizing exoplanets, even for tightly-orbiting exoplanets residing below the diffraction limit of the telescope. This research could pave the way for more effective methods to study Earth-like exoplanets and expand our understanding of planetary systems. Read the recent Universe Today article. Authors on the most recent article include: Nico Deshler, Itay Ozer, Amit Ashok, and Saikat Guha.
(a) Conceptual design of a quantum-optimal direct-imaging coronagraph based on spatial mode sorting. The forward mode sorter demultiplexes the field incident on the image plane into a PSF-adapted basis. Light in the fundamental mode is rejected by a mask at the sorting plane while light in the remaining modes propagates freely to an inverse mode sorter. The inverse mode sorter coherently recombines (multiplexes) the remaining modes to form an image at the detector. (b) Schematic of the experimental implementation of a quantum-optimal coronagraph using an MPLC mode sorter and non-reciprocal polarization elements. The MPLC is comprised of a sequence of diffractive phase elements designed to (de)multiplex Fourier-Zernike modes. A maximum likelihood estimator is applied on the captured image to localize the position of a sub-diffraction exoplanet.