Richard Tansey (Advanced Technology Center, Lockheed Martin), Henry Chan (Advanced Technology Center, Lockheed Martin), Avinash Honkan (Advanced Technology Center, Lockheed Martin)
Keywords: Adaptive Optics
Abstract:
A new adaptive optics device called a black fringe wavefront sensor ( bfwfs) has been developed over the last year at Lockheed Martins Advanced Technology Center.1 Current white light interferometry techniques used for microscopy surface height scans, as used in Linnick and Mirau Interferometers, are combined with am demodulation algorithms from the rf communication industry to produce a wavefront sensor capable of real time adaptive optics correction using white light or broadband multiline incoherent lasers or LEDs.
In this presentation the bfwfs will be described, and results of recent tests using a 16 channel device will be discussed. In addition, a planned 64 ch version being fabricated for a deformable mirror and Mems application will be described. The 16 ch device is used to obtain measurements of open loop influence functions, poke tests, and closed loop Bode plots using a Mems mirror.
The black fringe wavefront sensing device uses a fully parallel architecture and allows analog control of most wavefront correction devices used today including deformable mirrors, Mems, Liquid Crystal spatial light modulators, and Bimorphs. This control is obtained without the need for a complicated algorithm or computation, other then a minimum number of multiply and divide circuits as needed for peek seeking detection.
The bfwfs device can be used for adaptive optics at long ranges, on weight or volume limited platforms, because it allows high power incoherent lasers, or other sources, to be combined with a massively parallel architecture and inherently analog design.
Results are reported in which recently developed superluminescent laser diodes (SLDs) and high brightness white LEDs are tested for use with the black fringe wavefront sensor for long range atmospheric correction. Finally, a potential application of the bfwfs is discussed in which the recently discovered phenomena of white light filaments generated in the atmosphere by a fsec laser is proposed for guide star correction of images or directed energy propagation.
%Z Tansey,R.J., Black Fringe Wavefront Sensor, patent pending, 10/26/05, Lockheed Martin/Advanced Technology Center, 3251 Hanover St., Palo Alto, Ca., 94304
Date of Conference: September 10-14, 2006
Track: Adaptive Optics