TPF-I SWG Report - Exoplanet Exploration Program - NASA

C HAPTER 4
It should be noted that this calibration approach does carry some cost in the form of a more complex
beam-combination system (i.e., inserting a Mach-Zender interferometer into the system directly behind
the nuller) and some loss of photon flux (a fraction of the science beam must be mixed with the reference
beam). However, the amplitude and path-control requirements on this second beam combiner are nowhere
near as stringent as of the nulling system.
Figure 4-21. Simulated images reconstructed from raw and calibrated data, with three different noise
levels. Top: 1 nm of phase noise and 0.01% amplitude mismatch. Middle: 10 nm of phase noise and
0.1% amplitude mismatch. Bottom: 50 nm of phase noise and 0.5% amplitude mismatch.
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