Coronagraphic phase diversity: a simple focal plane sensor for high-contrast imaging

Area of Science:

• Astronomy and Astrophysics
• Optical Instrumentation

Background:

• Direct imaging of exoplanets is crucial for characterization but hindered by quasi-static speckles.
• These speckles stem from residual optical aberrations that require nanometric compensation.

Purpose of the Study:

• To introduce a novel focal plane wavefront sensor (WFS) for high-contrast imaging.
• To address the limitations imposed by optical aberrations in exoplanet detection.

Main Methods:

• Extension of the phase diversity technique to coronagraphic imaging.
• Utilizes two scientific images with a known aberration introduced by the adaptive optics subsystem.
• Calibrates aberrations down to the scientific camera without differential errors.

Main Results:

• Simulations demonstrate the potential of the proposed WFS.
• Preliminary experimental validation confirms its feasibility.

Conclusions:

• The novel WFS offers a hardware-independent solution for aberration correction in exoplanet imaging.
• This advancement can significantly improve the capabilities of future high-contrast imaging instruments.