Adaptive geometric optics derived from nonlinear acoustic effects

Higginson, Keith A.; Costolo, Michael A.; Rietman, Edward A.
February 2004
Applied Physics Letters;2/9/2004, Vol. 84 Issue 6, p843
Academic Journal
Tunable gradient index (GRIN) lenses were formed in a liquid-filled cavity supporting an ultrasonic standing wave. The refractive index gradient is based on the steady-state pressure component of the finite-amplitude acoustic signal. An acoustic lens was constructed which (1) focused and modulated a collimated light source and (2) formed an image. The properties of the lens are a function of the amplitude and frequency of the applied ultrasound. At the center of symmetry, the device can be approximated as a diverging lens with a single focal point of about -10 cm. In general, however, a series of focal lines are formed, to create a device resembling an axicon or an abberrating lens. © 2004 American Institute of Physics.


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