Advanced Wavefront Sensor Concepts.

Abstract : The objective of this effort was to investigate advances in wavefront sensor technology for use in future adaptive optics systems. The improvements sought over presently developed adaptive optics systems are preliminary in the areas of component efficiency and sub-system complexity, since this would have potential for major operational simplicity and reduced cost. The concept under study in this effort is the Large Scale Integrated Imaging Irradiance (LSI3) sensor. This is based on the Integrated Imaging Irradiance (I3) sensor (U.S. Patent No. 4,141,652). The I3 sensor is based on the Hartmann concepts, but does not suffer from the optical alignment problems inherent to previously developed Hartmann sensors. Another of the major advantages of the LSI3 sensor over the Hartmann sensors (including the previously developed I3 sensor) is that the LSI3 sensor utilizes the full aperture of the system in dividing the input photon flux into the respective quadrants which results in better diffraction - limited resolution. The LSI3 sensor is based on an optical system that is independent of the number of sub-apertures selected. The major tasks of this study included the conceptual design of a small version (approximately 20 channels), a large scale (approximately 200 channels) wavefront sensor, and the evaluation of the expected performance, complexity, and cost of these prototype models. The result of these design advancements is a new wavefront sensor (LSI3) which could provide cost and performance advances for future adaptive optics systems.