A high-contrast coronagraph for direct imaging of an Earth-like exoplanetat the visible band needs a contrast of 10E-10 at a small angular separation of 4λ/D or less. Here we report our recent laboratory experiment that approaches these limits.

Our test of a high-contrast imaging coronagraph is based on our step-transmissionapodized filter. To achieve this goal, we use a liquid crystal array as a phase correctorto create a dark hole based on our dedicated algorithm. We have suppressed thediffraction and speckle noise near the point image of a star to a level of 1.68E-9 at 4λ/D, which can be used for direct imaging of Jupiter-like exoplanets. This demonstrates that a telescope incorporating a high-contrast coronagraph in space has the potential to detect and characterize Earth-like planets.