In order to reach contrast ratios of 10−8 and beyond, coronagraph
testbeds need source optics that reliably emulate nearly-point-like starlight,
with microfabricated pinholes being a compelling solution. To verify, a
physical optics model of the Space Coronagraph Optical Bench (SCoOB) source
optics, including a finite-difference time-domain (FDTD) pinhole simulation,
was created. The results of the FDTD simulation show waveguide-like behavior of
pinholes. We designed and fabricated microfabricated pinholes for SCoOB made
from an aluminum overcoated silicon nitride film overhanging a silicon wafer
substrate, and report characterization of the completed pinholes.Comment: Submitted to SPIE Optical Engineering + Applications (OP23O