I proposed the Photonic Lantern Nuller (PLN) instrument concept for the efficient detection and spectroscopic characterization of exoplanets within the diffraction limit - a regime inaccessible to conventional coronagraphs. Accessing closer-in separations would greatly increase the expected number of detectable planets, which scales inversely with the inner working angle.
The PLN is a cross-aperture nuller that works by injecting light into a Mode-Selective Photonic Lantern (MSPL), leveraging the spatial symmetries of the device to cancel out on-axis starlight while letting off-axis planet light through. It was inspired by the Vortex Fiber Nuller concept - however, a PLN retains more of the planet flux than the VFN because of its multiple ports, so its ideal sensitivity is expected to be higher.
The PLN has been characterized in the lab in monochromatic and broadband light, and future work includes improving nulls using wavefront sensing and control, as well as an on-sky demonstration.