Light modulator employing electrooptic crystals
AssigneeKeuffel & Esser Company
InventorKent E. Erickson
Life of this patent
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Abstract
An electrooptic light modulator is constructed from a pair of subassemblies each comprising a lithium tantalate crystal fixed between two rigid, conductive electrodes. Such subassemblies may be individually tested to ensure the selection of a pair of crystals which are matching in thermal and electrical responses. The modulator construction is completed by arranging the selected subassembly pair with crystal optic axes in orthogonal relationship in order to negate the effects of natural crystal birefringence, and fixing the subassemblies between a pair of rigid pole pieces which, together with the electrodes, serve as heat sinks to moderate the effect of thermal fluctuations, and further stabilize the assembly against mechanical and piezoelectric perturbations.
Claims8
An electrooptic modulator comprising an assembly comprising:
- (a) a pair of electrooptic crystal subassemblies, each of which comprises:
- (i) an elongate, rectilinear, transparent crystal element consisting essentially of a compound exhibiting electrooptic birefringence, said crystal element having a transverse directional optic axis disposed perpendicular to two parallel opposing longitudinal faces of said crystal element and,
- (ii) a pair of rigid, elongate, electrically-conductive electrodes, each of which is affixed to and contiguous with a respective one of said opposing faces, thereby establishing, with respect to said directional optic axis, a front and a back electrode for said subassembly;
- (b) said subassembly pair being arranged end-to-end with the longitudinal axes of said crystal elements in line and the respective optic axes of said crystal elements disposed orthogonal to one another and to the longitudinal axis of said end-to-end arrangement;
- and
- (c) a pair of rigid, electrically-conductive pole pieces respectively affixed to and bridging the front electrode of the first and the back electrode of the second of said subassembly pair, and the front electrode of the second and the back electrode of the first of said subassembly pair.
The method of making an electrooptic modulator which comprises:
- (a) providing a pair of elongate, rectilinear, transparent crystal elements consisting essentially of a compound exhibiting electrooptic birefringence, each of said crystal elements having a transverse directional optic axis disposed perpendicular to two parallel opposing longitudinal faces thereof;
- (b) affixing contiguously to each of said longitudinal crystal element faces a rigid, elongate, electrically-conductive electrode, thereby constructing a pair of crystal subassembly units, each having, with respect to its individual directional optic axis, a front and a back electrode;
- (c) arranging said pair of subassembly units in an end-to-end relationship with the longitudinal axes of said crystal elements in line and the respective optic axes of said crystal elements orthogonal to one another and to the longitudinal axis of said end-to-end arrangement;
- (d) affixing a first rigid, electrically-conductive pole piece between the front electrode of the first and the back electrode of the second of said subassembly pair;
- and
- (e) affixing a second rigid, electrically-conductive pole piece between the back electrode of the first and the front electrode of the second of said subassembly pair;
- thereby forming a rigid, two-crystal electrooptic modulator assembly.
Dependencies are inferred from the claim text.