Boccaletti develops and exploits high-contrast coronagraphic imaging instrumentation for direct detection and characterization of exoplanets and circumstellar debris disks, including the four-quadrant phase-mask coronagraph built at Observatoire de Paris-PSL now flying on JWST's MIRI instrument, which recently resolved the inner dust belt and all four planets of the HR 8799 system in the mid-infrared.