Holographic microcavity modes enabled by metasurfaces (Invited Paper)

Optical microcavities have diverse applications in fields like quantum electrodynamics, semiconductor lasers, sensing, and nonlinear optics, but most microcavities are constrained to a few spatial mode profiles. Here, we present how dielectric metasurfaces can realize stable optical microcavities with holographic spatial mode profiles. We select a microscopic skier shape (20 x 20 um) as our desired mode profile. We then realize a Fabry-Perot-interferometer using two planar distributed Bragg reflectors (DBRs), with a metasurface placed on the surface of the second mirror. The metasurface is designed to negate the spatially dependent phase which the desired skier mode accumulates during one cavity round trip. By imaging the intracavity mode of the experimentally realized microcavity, we show that it selectively enhances light that couples to the desired skier mode at the design wavelength (633 nm). The holographic mode changes quickly with the cavity length, implying the possibility of implementing spatial profiles that change with cavity length. Dielectric metasurfaces provide phase and polarization control, suggesting polarization control in microcavities is also possible.