Richard Tansey (Advanced Technology Center, Lockheed Martin), Henry M. Chan (Advanced Technology Center, Lockheed Martin), Miguel Virgen (Advanced Technology Center, Lockheed Martin), Adam Phenis (Advanced Technology Center, Lockheed Martin)
Keywords: Atmospherics
Abstract:
The black fringe wavefront sensor (bfwfs) uses the peak of a visibility function, or the location of the maximum contrast fringe center as obtained in a self reference interferometer, to identify the zero optical path difference (opd) and resultant phase of a wavefront. The bfwfs is described in two previous papers (1, 2) and only a brief description will be described in this report. In the current work the first use of the the bfwfs for the measurement of atmospheric turbulence will be described. The drive voltage of a scanner mirror is synchronized to a max peak detector circuit to provide a real time voltage output which is equivalent to the phase (opd) at an array of subapertures. The surface height of a test object, or equivalently the opd due to atmospheric turbulence, is thus obtained.
An argon laser acts as a point source beacon for the sensor. Using a self-reference interferometer, the heterodyne beat from the dominant 514.5nm and 488nm lines produces a visibility function with minimum to minimum separations of 9470nm. Results of measurements of phase over an array of detectors will be shown , at several horizontal ranges. In addition, a complete closed loop adaptive optics system will be described using the black fringe wavefront sensor and a Mems mirror to correct atmospheric turbulence.
%Z R.J. Tansey, Chan, H., Honkan, A.A., The Black Fringe Wavefront Sensor: Real Time Adaptive Optics with Minimum Computation, AMOS 2007, Adaptive Optics Session
R.J. Tansey, A.A. Honkan, H.M.Chan, The Black Fringe Wavefront Sensor: White Light Real Time Analog Phase Measurement, SPIE , Photonics West 2007
Date of Conference: September 12-15, 2007
Track: Atmospherics