Browse Prior Art Database

Two Dimensional Optical Scanner

IP.com Disclosure Number: IPCOM000086814D
Original Publication Date: 1976-Oct-01
Included in the Prior Art Database: 2005-Mar-03
Document File: 2 page(s) / 45K

Publishing Venue

IBM

Related People

Wilkinson, CD: AUTHOR

Abstract

The interaction of acoustic waves and light in a parametric signal processor is employed, as shown, to provide a two-dimensional optical scanning device.

This text was extracted from a PDF file.
At least one non-text object (such as an image or picture) has been suppressed.
This is the abbreviated version, containing approximately 71% of the total text.

Page 1 of 2

Two Dimensional Optical Scanner

The interaction of acoustic waves and light in a parametric signal processor is employed, as shown, to provide a two-dimensional optical scanning device.

As described for example, by L. A. Coldren in Applied Physics Letters, Vol. 27, No. 1, July 1, 1975, a parametric signal processor produces an electrical signal train as a function of the intensity of illumination incident upon the device when it is interrogated by two oppositely travelling acoustic waves, one a continuous wave and the other a pulse.

In the drawing a sonic transducer 10 launches a first sonic pulse in parallel into each of the ridged silicon waveguides 11-18, each of which is of a slightly different length. The sonic wave reaches the end of each waveguide, at a different time, as a function of the length and is returned as an echo. The echo waves are, therefore, time-spaced as to the waveguides. When a second, or interrogated, pulse is launched by the sonic transducer 10, it meets each of the echo waves at a different time. The signal at the output terminal of convolver 20 is a series of time-spaced electrical pulses, the magnitude of which is a function of the intensity of illumination incident upon each waveguide at the point of intersection of the two acoustic waves.

The locus of the points on the waveguides interrogated by any one pulse is a line parallel to the boundary line of the stepped ends of the variable length waveguides. By varying the timing of the s...