Low Intensity Optical Beam for Addressable Acoustic Generation
Original Publication Date: 1978-Mar-01
Included in the Prior Art Database: 2005-Feb-20
A capacitor-like arrangement is shown in the drawing with a photoconductor 14 as the dielectric in order to generate acoustic waves in localized regions accessed by a pulsed light beam 19. The light produces a lowering of the resistance at the point of contact with the photoconductor 14, and absorption thereby alters the electric field locally. Acoustic waves in the megahertz range can be generated with submicrosecond pulses. The actual frequency is determined by the electron-hole transit time across the photoconductor as well as the lifetime of the photo-generated carriers.