Real-time holographic display: Improvements using a multi-channel acousto-optic modulator and holographic optical elements
Pierre St-Hilaire, Stephen A. Benton, Mark Lucente, John Underkoffler,
Spatial Imaging Group
MIT Media Laboratory
Any practical holographic display device relying on the MIT synthetic
aperture approach will require time-bandwith products far exceeding
those available with single channel acousto-optic modulators (AOMs).
A solution to this problem is to use a multichannel AOM, thus making
use of the parallelism inherent in optical systems. It is now
technically feasible to accomodate a large number of acoustic channels
on a single crystal with a corresponding improvement in image
The vertical view zone also becomes a significant problem for any
large size display since each horizontal scan line line is visible
only from a narrow angle in the vertical direction. Using holographic
optical elements (HOEs) alleviates this limitation in two ways: First,
the interline spacing can be adjusted easily with HOEs. Second, it is
possible to manufacture an HOE which will act as a one-dimensional
diffuser. Placing such an HOE in the vertical focus plane of the
display increases the view zone by diffusing each line in the vertical
direction, but leaves the horizontal image content unaltered.
P. St.-Hilaire, S. A. Benton, M. Lucente, J.S. Underkoffler, and H.
Yoshikawa, "Real-time Holographic Display: improvements using
multi-channel acousto-optic modulators and holographic optical
elements," in: S.A. Benton, ed., SPIE Vol. 1461, Practical
Holography V, (Feb. 1991) pp. 254-261.
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