Optical element mounted on a base having a capacitor imbedded therein

Claim 2

An optical device, comprising: a base including a lower cylindrical base member having a central line and a first diameter and having a top surface and a bottom surface opposite to the top surface, a first electrode layer on the top surface of the lower base member, a dielectric layer on the first electrode, a second electrode layer on the dielectric layer, and an upper base member on the second electrode layer, the upper base member including a first cylindrical portion having a central line identical with the central line of the lower cylindrical base member and a diameter equal to the first diameter, and having a top surface and a bottom surface opposite to the top surface, the bottom surface of the first cylindrical portion facing the second electrode layer, and a second cylindrical portion having a central line identical with the central line of the first cylindrical member and a second diameter smaller than the first diameter and having a top surface and a bottom surface facing the top surface of the first cylindrical portion; a plurality of elongated leads supported by said base, said leads being elongated so as to protrude from the bottom surface of the lower base member; a ring-shaped flange on the top surface of the first cylindrical portion of the upper base member, said ring-shaped flange protruding from a side surface of said base; a conductive pattern formed on the top surface of the second cylindrical portion of the upper base member, said conductive pattern being electrically coupled to said leads; and a photo diode mounted on the center of the top surface of the second cylindrical portion of the upper base member, so that the position of the photo diode is determined by the upper base member.

Claim 3

An optical device according to claim 1, wherein said upper and lower base members are made of ceramic.

Claim 4

An optical device according to claim 2, wherein each of said upper and lower base members is composed of a plurality of first ceramic plates.

Claim 5

An optical device according to claim 3, wherein each of the first ceramic plates has a thickness of 0.4 mm.

Claim 6

An optical device according to claim 1, wherein said first and second electrode layers are printed electrode layers.

Claim 7

An optical device according to claim 1, wherein said dielectric layer is composed of a plurality of second ceramic plates.

Claim 8

An optical device according to claim 6, wherein each of the second ceramic plates has a thickness of 50 μm.

Claim 9

An optical device comprising: a first lead for applying a first voltage level; a second lead for applying a second voltage level; a lower cylindrical base member having a central line and a first diameter and having a top surface and a bottom surface opposite to the top surface, said lower cylindrical base member supporting said first and second leads, said first and second leads being elongated so as to protrude from the bottom surface of the lower base cylindrical member; a capacitor on the top surface of the lower cylindrical base member, said capacitor having, a first electrode layer on the top surface of the lower cylindrical base member, the first electrode layer being electrically coupled to the first lead, a dielectric layer on the first electrode, and a second electrode layer on the dielectric layer, the second electrode layer being electrically coupled to the second lead; an upper base member on the second electrode layer, the upper base member including a first cylindrical portion having a central line identical with the central line of the lower cylindrical base member and a diameter equal to the first diameter, and having a top surface and a bottom surface opposite to the top surface, the bottom surface of the first cylindrical portion facing the second electrode layer, and a second cylindrical portion having a central line identical with the central line of the first cylindrical portion and a second diameter smaller than the first diameter, and having a top surface and a bottom surface facing the top surface of the first cylindrical portion; a ring-shaped flange on the top surface of the first cylindrical portion of the upper base member and protruding from a side surface of said upper base member; first and second conductive patterns formed on the top surface of the first cylindrical portion of the upper base member, said first and second conductive patterns being electrically coupled to said first and second leads, respectively; and a photo diode mounted on the center of the top surface of the first cylindrical portion of the upper base member, so that the position of the photo diode is determined by the upper base member.

Claim 10

An optical device comprising: a first lead for applying a first voltage level; a second lead for applying a second voltage level; a lower cylindrical base member having a central line and a first diameter and having a top surface and a bottom surface opposite to the top surface, said lower cylindrical base member supporting said first and second leads, said first and second leads being elongated so as to protrude from the bottom surface of the lower base cylindrical member; a capacitor on the top surface of the lower cylindrical base member, said capacitor having, a first electrode layer on the top surface of the lower cylindrical base member, the first electrode layer being electrically coupled to the first lead, a dielectric layer on the first electrode, and a second electrode layer on the dielectric layer, the second electrode layer being electrically coupled to the second lead; an upper base member on the second electrode layer, the upper base member including a first cylindrical portion having a central line identical with the central line of the lower cylindrical base member and a diameter equal to the first diameter, and having a top surface and a bottom surface opposite to the top surface, the bottom surface of the first cylindrical portion facing the second electrode layer, and a second cylindrical portion having a central line identical with the central line of the first cylindrical portion and a second diameter smaller than the first diameter, and having a top surface and a bottom surface facing the top surface of the first cylindrical portion; a ring-shaped flange on the top surface of the first cylindrical portion of the upper base member and protruding from a side surface of said upper base member; first and second conductive patterns formed on the top surface of the first cylindrical portion of the upper base member, said first and second conductive patterns being electrically coupled to said first and second leads, respectively; and a photo diode mounted on the center of the top surface of the first cylindrical portion of the upper base member, so that the position of the photo diode is determined by the upper base member.

Claim 11

An optical device according to claim 8, wherein said upper base member and lower cylindrical base member are made of ceramic.

Claim 12

An optical device according to claim 9, wherein each of said upper base member and lower cylindrical base member is composed of a plurality of first ceramic plates.

Claim 13

An optical device according to claim 10, wherein each of the first ceramic plates has a thickness of 0.4 mm.

Claim 14

An optical device according to claim 8, wherein said first and second electrode layers are printed electrode layers.

Claim 15

An optical device according to claim 8, wherein said dielectric layer is composed of a plurality of second ceramic plates.

Claim 16

An optical device according to claim 13, wherein each of the second ceramic plates has a thickness of 50 μm.

Claim 17

An optical device comprising: a first lead for applying a first voltage level; a second lead for applying a second voltage level; a base having first and second top surfaces and a bottom surface and having first and second through holes both of which pass from the first top surface to the bottom surface of said base, the first and second through holes having inner conductive layers which are electrically coupled to said first and second leads respectively, said base including a lower cylindrical base member having a central line and a first diameter and having a top surface and a bottom surface opposite to the top surface, the lower cylindrical base member supporting said first and second leads, the first and second leads being elongated so as to protrude from the bottom surface of the lower cylindrical base member, the bottom surface of the lower cylindrical base member being identical with the bottom surface of said base, a first electrode layer on the top surface of the lower cylindrical base member, the first electrode layer being electrically coupled to the inner conductive layer of the first through hole, a dielectric layer on the first electrode layer, a second electrode layer on the dielectric layer, the second electrode layer being electrically coupled to the inner conductive layer of the second through hole, and an upper base member on the second electrode layer, the upper base member including a first cylindrical portion having a central line identical with the central line of the lower cylindrical base member and a diameter equal to the first diameter, and having a top surface and a bottom surface opposite to the top surface, the bottom surface of the first cylindrical portion facing the second electrode layer, the top surface of the first cylindrical portion being identical with the second top surface of said base, and a second cylindrical portion having a central line identical with the central line of the first cylindrical portion and a second diameter smaller than the first diameter, and having a top surface and a bottom surface facing the top surface of the first cylindrical portion, the top surface of the second cylindrical portion being identical with the first top surface of said base; first and second conductive patterns on the first top surface of said base, said first and second conductive patterns being electrically coupled to the inner conductive layers of the first and second through holes respectively; and a photo diode mounted on the center of the first top surface of said base, so that the position of the photo diode is determined by the upper base member.

Claim 18

An optical device comprising: a first lead for applying a first voltage level; a second lead for applying a second voltage level; a base having first and second top surfaces and a bottom surface and having first and second through holes both of which pass from the first top surface to the bottom surface of said base, the first and second through holes having inner conductive layers which are electrically coupled to said first and second leads respectively, said base including a lower cylindrical base member having a central line and a first diameter and having a top surface and a bottom surface opposite to the top surface, the lower cylindrical base member supporting said first and second leads, the first and second leads being elongated so as to protrude from the bottom surface of the lower cylindrical base member, the bottom surface of the lower cylindrical base member being identical with the bottom surface of said base, a first electrode layer on the top surface of the lower cylindrical base member, the first electrode layer being electrically coupled to the inner conductive layer of the first through hole, a dielectric layer on the first electrode layer, a second electrode layer on the dielectric layer, the second electrode layer being electrically coupled to the inner conductive layer of the second through hole, and an upper base member on the second electrode layer, the upper base member including a first cylindrical portion having a central line identical with the central line of the lower cylindrical base member and a diameter equal to the first diameter, and having a top surface and a bottom surface opposite to the top surface, the bottom surface of the first cylindrical portion facing the second electrode layer, the top surface of the first cylindrical portion being identical with the second top surface of said base, and a second cylindrical portion having a central line identical with the central line of the first cylindrical portion and a second diameter smaller than the first diameter, and having a top surface and a bottom surface facing the top surface of the first cylindrical portion, the top surface of the second cylindrical portion being identical with the first top surface of said base; first and second conductive patterns on the first top surface of said base, said first and second conductive patterns being electrically coupled to the inner conductive layers of the first and second through holes respectively; and a photo diode mounted on the center of the first top surface of said base, so that the position of the photo diode is determined by the upper base member.

Claim 19

An optical device according to claim 15, wherein the upper base member and lower cylindrical base member are made of ceramic.

Claim 20

An optical device according to claim 16, wherein each of the upper base member and lower cylindrical base member is composed of a plurality of first ceramic plates.

Claim 21

An optical device according to claim 17, wherein each of the first ceramic plates has a thickness of 0.4 mm.

Claim 22

An optical device according to claim 15, wherein said dielectric layer is composed of a plurality of second ceramic plates.

Claim 23

An optical device according to claim 19, wherein each of the second ceramic plates has a thickness of 50 μm.

Claim 24

An optical device according to claim 15, further comprising a first flange that is disposed on the top surface of said first cylindrical portion and that protrudes from a side surface of said first cylindrical portion, and a cap covering said conductive patterns, said photo diode and said second cylindrical portion, said cap having a second flange which is joined to said first flange.

Claim 25

An optical device according to claim 21, wherein said first and second flanges are metallic.

Claim 26

An optical device according to claim 21, wherein said first and second flanges and the first and second leads are formed of the same material.

Claim 27

An optical device according to claim 8, wherein said flange is a first flange that protrudes from a side surface of said first cylindrical portion, and further comprising a cap covering said conductive patterns, said photo diode and said second cylindrical portion, said cap having a second flange which is joined to said first flange.

Claim 28

An optical device according to claim 24, wherein said first and second flanges are metallic.

Claim 29

An optical device according to claim 24, which in said first and second flanges and the first and second leads are formed of the same material.

Claim 30

An optical device according to claim 1, further comprising a first flange that protrudes from a side surface of said first cylindrical portion, and a cap covering said conductive pattern, said photo diode and said second cylindrical portion, said cap having a second flange which is joined to said first flange.

Claim 31

An optical device according to claim 27, wherein said first and second flanges are metallic.

Claim 32

An optical device according to claim 27, wherein said first and second flanges and said leads are formed of the same material.