Electrooptic modulation element
AssigneeNippon Telegraph and Telephone Corporation
InventorsAiichirou Sasaki, Mitsuru Shinagawa
Life of this patent
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Abstract
On one pair of opposed side faces (1a, 1b) of electro-optic crystal (1), grooves (3a, 3b) are formed so as to make bottom faces of the grooves approach each other and make a distance between the bottom faces shorter than a predetermined distance, and the pair of electrodes (5a, 5b) are formed in the grooves (3a, 3b) so as to fill the grooves nearly completely.
Claims27
An electro-optic modulation device that includes electro-optic crystal (1) having a birefringence index changed by a coupled electric field, and one pair of electrodes (5a, 5b) disposed so as to have the electro-optic crystal interposed therebetween to couple the electric field to the electro-optic crystal, and that changes polarization of light incident between the one pair of electrodes according to a change of the birefringence index depending upon a strength of electric field coupled via the one pair of electrodes, wherein
- the electro-optic crystal (1) comprises grooves (3a, 3b) parallel to a direction of the incident light respectively on one pair of side faces parallel to the direction, and consequently a thin crystal portion sandwiched between the grooves serves as a portion for coupling the electric field, and
- the one pair of electrodes (5a, 5b) are formed so as to fill the grooves (3a, 3b), respectively.
An electro-optic modulation device that includes electro-optic crystal (1) having a birefringence index changed by a coupled electric field, and one pair of electrodes (7a, 7b;
- 7aa, 7bb) disposed so as to have the electro-optic crystal interposed therebetween to couple the electric field to the electro-optic crystal, and that changes polarization of light incident between the one pair of electrodes according to a change of the birefringence index depending upon a strength of electric field coupled via the one pair of electrodes, wherein
- the electro-optic crystal (1) comprises grooves (3a, 3b;
- 4a, 4b) parallel to a direction of the incident light respectively on one pair of side faces parallel to the direction, and consequently a thin crystal portion sandwiched between the grooves serves as a portion for coupling the electric field,
- the one pair of electrodes (7a, 7b;
- 7aa, 7bb) are formed in bottom portions of the grooves (3a, 3b;
- 4a, 4b) so as to have a predetermined thickness, and
- at least remaining portions of the grooves (3a, 3b;
- 4a, 4b) except the one pair of electrode portions are filled with insulators (9a, 9b;
- 9aa, 9ba;
- 10;
- 10a, 10b).
An electro-optic modulation device that includes electro-optic crystal (1;
- 61;
- 61A) having a birefringence index changed by a coupled electric field, and one pair of electrodes (25a, 25b;
- 29a, 29b;
- 64a, 64b) disposed so as to have the electro-optic crystal interposed therebetween to couple the electric field to the electro-optic crystal, and that changes polarization of light incident between the one pair of electrodes according to a change of the birefringence index depending upon a strength of electric field coupled via the one pair of electrodes, the electro-optic modulation device comprising:
- a base portion (63);
- and
- a ridge-shaped ridge portion (21;
- 21a;
- 64) projected on one side face of the base portion (63) and extended in a direction of the incident light, at least a part of the ridge portion comprising the electro-optic crystal, the ridge portion having a width equivalent to a predetermined value or less,
- wherein the one pair of electrodes (25a, 25b;
- 29a, 29b;
- 64a, 64b) are formed on one pair of side faces opposed in a width direction of the ridge portion (21;
- 21a;
- 64).
An electro-optic modulation device that includes electro-optic crystal (31) having a birefringence index changed by a coupled electric field, and one pair of electrodes (33, 35) disposed so as to have the electro-optic crystal interposed therebetween to couple the electric field to the electro-optic crystal, and that changes polarization of light incident between the one pair of electrodes according to a change of the birefringence index depending upon a strength of electric field coupled via the one pair of electrodes, the electro-optic modulation device further comprising:
- an insulator (37) applied so as to relatively fix the electro-optic crystal (31) and the one pair of electrodes (33, 35), except end faces through which light is incident or emitted.
Dependencies are inferred from the claim text.