Acoustic transducers having localized ferroelectric domain inverted regions
AssigneeGooch and Housego PLC
InventorChristopher N. Pannell
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Abstract
An acoustic transducer comprises a ferroelectric crystal having a plurality of spaced apart ferroelectric domain inverted regions and at least one non-inverted region. An electrode layer is disposed on one side of the crystal electrically contacting both the domain inverted portion and the non-inverted portion of the crystal. On a side of the crystal opposite the electrode layer, a first electrode is disposed on the domain inverted portion spaced apart from a second electrode disposed on the non-inverted portion. As a result, the acoustic transducer provides sub-transducers hooked in series having effective areas defined by the areas of their respective electrodes.
Claims22
An acoustic transducer, comprising:
- a non z-cut ferroelectric crystal including a plurality of spaced apart domain inverted portions and at least one non-inverted portion;
- a first electrode layer consisting of a single electrode on one side of said ferroelectric crystal contacting both said domain inverted portions and said non-inverted portion, and
- a second electrode layer on a side of said ferroelectric crystal opposite said first electrode layer.
An acousto-optic (AO) device for generating a highly apodized acoustic wave field, comprising:
- an acoustic transducer for emitting an acoustic wave, comprising:
- a non z-cut ferroelectric crystal consisting of one crystal including a plurality of spaced apart domain inverted portions and at least one non-inverted portion;
- a bottom electrode layer on one side of said ferroelectric crystal contacting both said domain inverted portions and said non-inverted portion of said ferroelectric crystal, and
- on a side of said ferroelectric crystal opposite said bottom electrode layer a top electrode layer, and
- an AO interaction crystal receiving said acoustic wave attached to said bottom electrode layer, for receiving an acoustic wave launched by said transducer,
- wherein at least one of said bottom and said top electrode consists of a single electrode.
A method of dynamically steering an acoustic beam using a transducer consisting of one non z-cut ferroelectric crystal having a plurality of domain inverted portions and at least one non-inverted portion, and a top electrode and a bottom electrode on opposite sides of said ferroelectric crystal coupled to an AO crystal, comprising the steps of:
- applying an electrical signal at an acoustic frequency across said electrodes to launch a longitudinal or shear acoustic wave field into said AO crystal, wherein said acoustic wave field includes a plurality of in phase and 180 degree phase reversal regions with respect to position on said transducer defined by a distribution of said non-inverted and said domain inverted portions, and
- time varying said acoustic frequency, wherein an angle of the acoustic wave emitted by said transducer relative to a normal of said transducer changes as a function of said acoustic frequency.
Dependencies are inferred from the claim text.