High contrast and high resolution sensing and correction of atmospheric turbulence without WFSs and DMs using a digital signal modulated satellite beacon and integrated photonics devices

For high contrast imaging, atmospheric turbulence may be sensed and corrected at very high band-width without Wavefront Sensors (WFS) or deformable mirrors using phase correcting integrated photonics devices and advanced signal processing. The overall system employs radio astronomy techniques developed for clock distribution, to sense and correct phase, and radio interferometry procedures to produce high resolution images. One of the tallest poles in high-contrast AO is the frame rate. Our simulation models estimate correction band-width can be 1-2 orders of magnitude faster than current high contrast Adaptive Optics (AO). The method employs a satellite loitering near a science object to send a coded reference laser to the telescope. We have designed and measured a 32 channel astrophotonics phase sensing and correcting device, which is low-cost and compact due to its telecommunications heritage. We are developing a prototype AO system to test the concept, first on a bench and then using a telescope pointed at sources on a tower. This paper also describes how the scheme may be extended to arrays of optical telescopes to give unprecedented micro-arcsecond resolution in the near infrared to obtain image and spectral data cubes of extrasolar planets. The method is also useful for satellite communications, and we have applied for a patent for both astronomy and communications.