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US5652674A Expired / Lapsed US ⏱️ 0.0 years remaining

Method for manufacturing domain-inverted region, optical wavelength conversion device utilizing such domain-inverted region and method for fabricating such device

Assignee: Panasonic Holdings Corp
•
Filing: 1995-08-30
•
Granted: 1997-07-29
•
Expires: 2015-08-30
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Abstract

Abstract A comb-shaped electrode and a planar electrode are formed on a surface and a bottom face of a substrate. Then, a DC voltage on which a pulse voltage is superimposed is applied to the electrodes using a DC power source and a pulse power source so as to apply a DC electric field on which a pulse electric field is superimposed to the substrate. As a result, periodic domain-inverted regions are formed by applying even a small pulse electric field. Since the applied electric field is highly uniform in a face of the substrate, the domain-inverted regions having a uniform periodic structure are formed. Alternatively, after the comb-shaped electrode is covered with an insulating film, the pulse voltage is applied to the electrodes using the pulse power source so as to apply the pulse electric field to the substrate. As a result, since movement of free charges in the surface of a crystal is restrained so as to inhibit the spread of domain inversion in a horizontal direction, a uniform short-periodic domain-inverted structure is formed. According to the present invention, deep short-periodic domain-inverted regions are uniformly formed over a large area of the substrate. As a result, an optical wavelength conversion device having a short wavelength with high efficiency can be manufactured.

Inventors

  • 👤 Kiminori Mizuuchi
  • 👤 Kazuhisa Yamamoto

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-11-08 04:15
CPC Classifications
G; G02; G02F; G02F1/00; G02F1/35; G02F1/37; G02F1/377; G02F1/3775; G02F1/355; G02F1/3558; G02F1/353; G02F1/3544; G02F1/3548

Claims Analysis

Total Claims: 85
Claim 1
Independent Claim 91 words
A method for manufacturing a domain-inverted region, comprising the steps of: forming a first electrode and a second electrode on a ferroelectric crystal substrate, the first and second electrodes being separated in a domain direction of the ferroelectric crystal substrate; applying a DC voltage between the first electrode and the second electrode; and inverting a domain of a predetermined region in the ferroelectric crystal substrate by applying a combined voltage of the DC voltage and a pulse voltage, the combined voltage obtainable by superimposing the pulse voltage on the DC voltage.
Claim 2
Independent Claim 91 words
A method for manufacturing a domain-inverted region, comprising the steps of: forming a first electrode and a second electrode on a ferroelectric crystal substrate, the first and second electrodes being separated in a domain direction of the ferroelectric crystal substrate; applying a DC voltage between the first electrode and the second electrode; and inverting a domain of a predetermined region in the ferroelectric crystal substrate by applying a combined voltage of the DC voltage and a pulse voltage, the combined voltage obtainable by superimposing the pulse voltage on the DC voltage.
Claim 3
Dependent Claim 47 words
A method according to claim 1, wherein a level of the DC voltage is smaller than a voltage level at which domain inversion occurs, and a level of the combined voltage is substantially equal to or larger than the voltage level at which the domain inversion occurs.
Claim 4
Dependent Claim 22 words
A method according to claim 1, wherein at least one of the first electrode and the second electrode is a comb-shaped electrode.
Claim 5
Dependent Claim 21 words
A method according to claim 3, wherein the comb-shaped electrode is formed on a +C face of the ferroelectric crystal substrate.
Claim 6
Dependent Claim 23 words
A method according to claim 1, wherein the domain direction of the ferroelectric crystal substrate is perpendicular to a surface of the substrate.
Claim 7
Dependent Claim 32 words
A method according to claim 5, wherein the ferroelectric crystal substrate is made of a material selected from a group consisting of LiNb.sub.(1-x) Ta x O 3 (0≦x≦1) and KTiOPO 4 .
Claim 8
Dependent Claim 31 words
A method according to claim 1, further comprising the steps of: removing the first electrode and the second electrode; and thermally treating the ferroelectric crystal substrate at 580° C. or lower.
Claim 9
Dependent Claim 42 words
A method according to claim 1, further comprising the step of: deteriorating ferroelectricity of the ferroelectric crystal substrate in a periphery of at least one of the first electrode and the second electrode prior to the step of applying the DC voltage.
Claim 10
Dependent Claim 64 words
A method according to claim 1, wherein the first electrode is formed on a first face of the ferroelectric crystal substrate and the second electrode is formed on a second face of the ferroelectric crystal substrate which is opposite to the first face, the domain direction of the ferroelectric crystal substrate being perpendicular to the first and second faces of the ferroelectric crystal substrate.
Claim 11
Independent Claim 125 words
A method for manufacturing a domain-inverted region, comprising the steps of: forming a first electrode and a second electrode on a ferroelectric crystal substrate, the first and second electrodes being separated from each other in a domain direction of the ferroelectric crystal substrate; deteriorating ferroelectricity of the ferroelectric crystal substrate in a periphery of at least one of the first electrode and the second electrode; and inverting a domain of a predetermined region in the ferroelectric crystal substrate by applying a predetermined voltage between the first electrode and the second electrode, wherein at least one of the first electrode and the second electrode is a comb-shaped electrode, and the ferroelectricity is deteriorated in a gap between at least two electrode branches of the comb-shaped electrode.
Claim 12
Independent Claim 125 words
A method for manufacturing a domain-inverted region, comprising the steps of: forming a first electrode and a second electrode on a ferroelectric crystal substrate, the first and second electrodes being separated from each other in a domain direction of the ferroelectric crystal substrate; deteriorating ferroelectricity of the ferroelectric crystal substrate in a periphery of at least one of the first electrode and the second electrode; and inverting a domain of a predetermined region in the ferroelectric crystal substrate by applying a predetermined voltage between the first electrode and the second electrode, wherein at least one of the first electrode and the second electrode is a comb-shaped electrode, and the ferroelectricity is deteriorated in a gap between at least two electrode branches of the comb-shaped electrode.
Claim 13
Dependent Claim 18 words
A method according to claim 10, wherein the step of deteriorating the ferroelectricity employs a proton exchange treatment.
Claim 14
Dependent Claim 67 words
A method according to claim 10, wherein the ferroelectric crystal substrate is a C plate substrate which is cut along a face perpendicular to a C axis of a crystal, and the first electrode and the second electrode are a comb-shaped electrode formed on a first face of the C plate substrate and a planar electrode formed on a second face of the C plate substrate, respectively.
Claim 15
Dependent Claim 21 words
A method according to claim 12, wherein a nucleus for domain inversion is generated in a vicinity of the first face.
Claim 16
Dependent Claim 33 words
A method according to claim 12, wherein a width of each electrode branch included in the comb-shaped electrode is equal to or smaller than a half of an interval between the electrode branches.
Claim 17
Dependent Claim 35 words
A method according to claim 12, further comprising the step of removing a vicinity of at least one of the first face and the second face of the C plate substrate to a predetermined depth.
Claim 18
Dependent Claim 48 words
A method according to claim 12, wherein the C plate substrate is made of a material selected from a group consisting of LiNb.sub.(1-x) Ta x O 3 (0≦x≦1) and KTiOPO 4 , and the first face is a +C face and the second face is a -C face.
Claim 19
Dependent Claim 18 words
A method according to claim 16, wherein the step of deteriorating the ferroelectricity employs a proton exchange treatment.
Claim 20
Dependent Claim 30 words
A method according to claim 16, further comprising the steps of: removing the first electrode and the second electrode; and annealing the ferroelectric crystal substrate at 500° C. or lower.
Claim 21
Dependent Claim 14 words
A method according to claim 10, wherein the predetermined voltage is a pulse voltage.
Claim 22
Dependent Claim 24 words
A method according to claim 10, wherein the predetermined voltage is a combined voltage obtainable by superimposing a pulse voltage on a DC voltage.
Claim 23
Dependent Claim 22 words
A method according to claim 10, wherein at least one of the first electrode and the second electrode is a comb-shaped electrode.
Claim 24
Dependent Claim 31 words
A method according to claim 10, the ferroelectric crystal substrate is made of a material selected from a group consisting of LiNb.sub.(1-x) Ta x O 3 (0≦x≦1) and KTiOPO 4 .
Claim 25
Dependent Claim 67 words
A method according to claim 10, wherein the ferroelectric crystal substrate is a C plate substrate which is cut along a face perpendicular to a C axis of a crystal, and the first electrode and the second electrode are a comb-shaped electrode formed on a first face of the C plate substrate and a planar electrode formed on a second face of the C plate substrate, respectively.
Claim 26
Dependent Claim 21 words
A method according to claim 23, wherein a nucleus for domain inversion is generated in a vicinity of the first face.
Claim 27
Dependent Claim 33 words
A method according to claim 23, wherein a width of each electrode branch included in the comb-shaped electrode is equal to or smaller than a half of an interval between the electrode branches.
Claim 28
Dependent Claim 48 words
A method according to claim 23, wherein the C plate substrate is made of a material selected from a group consisting of LiNb.sub.(1-x) Ta x O 3 (0≦x≦1) and KTiOPO 4 , and the first face is a +C face and the second face is a -C face.
Claim 29
Dependent Claim 64 words
A method according to claim 10, wherein the first electrode is formed on a first face of the ferroelectric crystal substrate and the second electrode is formed on a second face of the ferroelectric crystal substrate which is opposite to the first face, the domain direction of the ferroelectric crystal substrate being perpendicular to the first and second faces of the ferroelectric crystal substrate.
Claim 30
Independent Claim 133 words
A method for manufacturing a domain-inverted region, comprising the steps of: forming a first electrode and a second electrode on a ferroelectric crystal substrate, the first and second electrodes being separated from each other in a domain direction of the ferroelectric crystal substrate; shaving off a surface of the ferroelectric crystal substrate in a vicinity of at least one of the first electrode and the second electrode; and inverting a domain of a predetermined region in the ferroelectric crystal substrate by applying a predetermined voltage between the first electrode and the second electrode, wherein at least one of the first electrode and the second electrode is a comb-shaped electrode, and the surface of the ferroelectric crystal substrate is shaved off in a gap between at least two electrode branches of the comb-shaped electrode.
Claim 31
Independent Claim 133 words
A method for manufacturing a domain-inverted region, comprising the steps of: forming a first electrode and a second electrode on a ferroelectric crystal substrate, the first and second electrodes being separated from each other in a domain direction of the ferroelectric crystal substrate; shaving off a surface of the ferroelectric crystal substrate in a vicinity of at least one of the first electrode and the second electrode; and inverting a domain of a predetermined region in the ferroelectric crystal substrate by applying a predetermined voltage between the first electrode and the second electrode, wherein at least one of the first electrode and the second electrode is a comb-shaped electrode, and the surface of the ferroelectric crystal substrate is shaved off in a gap between at least two electrode branches of the comb-shaped electrode.
Claim 32
Dependent Claim 27 words
A method according to claim 28, further comprising the step of covering at least one of the first electrode and the second electrode with an insulating film.
Claim 33
Dependent Claim 14 words
A method according to claim 29, wherein the insulating film is a dielectric film.
Claim 34
Dependent Claim 19 words
A method according to claim 29, wherein a resistivity of the insulating film is larger than 10 15 Ω/cm.
Claim 35
Dependent Claim 14 words
A method according to claim 28, wherein the predetermined voltage is a pulse voltage.
Claim 36
Dependent Claim 24 words
A method according to claim 28, wherein the predetermined voltage is a combined voltage obtainable by superimposing a pulse voltage on a DC voltage.
Claim 37
Dependent Claim 32 words
A method according to claim 28, wherein the ferroelectric crystal substrate is made of a material selected from a group consisting of LiNb.sub.(1-x) Ta x O 3 (0≦x≦1) and KTiOPO 4 .
Claim 38
Dependent Claim 32 words
A method according to claim 28, wherein a width of each electrode branch included in the comb-shaped electrode is equal to or smaller than half of an interval between the electrode branches.
Claim 39
Dependent Claim 87 words
A method according to claim 28, wherein the ferroelectric crystal substrate is a C plate substrate which is cut along a face perpendicular to a C axis of a crystal, the first electrode and the second electrode are a comb-shaped electrode formed on a first face of the C plate substrate and a planar electrode formed on a second face of the C plate substrate, respectively, and a surface of the ferroelectric crystal substrate is shaved off in a gap between electrode branches of the comb-shaped electrode.
Claim 40
Dependent Claim 21 words
A method according to claim 36, wherein a nucleus for domain inversion is generated in a vicinity of the first face.
Claim 41
Dependent Claim 48 words
A method according to claim 36, wherein the C plate substrate is made of a material selected from a group consisting of LiNb.sub.(1-x) Ta x O 3 (0≦x≦1) and KTiOPO 4 , and the first face is a +C face and the second face is a -C face.
Claim 42
Dependent Claim 64 words
A method according to claim 28, wherein the first electrode is formed on a first face of the ferroelectric crystal substrate and the second electrode is formed on a second face of the ferroelectric crystal substrate which is opposite to the first face, the domain direction of the ferroelectric crystal substrate being perpendicular to the first and second faces of the ferroelectric crystal substrate.
Claim 43
Independent Claim 70 words
A method for manufacturing a domain-inverted region, comprising the steps of: forming a first electrode and a second electrode on a ferroelectric crystal substrate, the first and second electrodes being separated from each other in a domain direction of the ferroelectric crystal substrate; and inverting a domain of a predetermined region in the ferroelectric crystal substrate by applying a predetermined magnetic field between the first electrode and the second electrode.
Claim 44
Independent Claim 70 words
A method for manufacturing a domain-inverted region, comprising the steps of: forming a first electrode and a second electrode on a ferroelectric crystal substrate, the first and second electrodes being separated from each other in a domain direction of the ferroelectric crystal substrate; and inverting a domain of a predetermined region in the ferroelectric crystal substrate by applying a predetermined magnetic field between the first electrode and the second electrode.
Claim 45
Dependent Claim 16 words
A method according to claim 40, wherein the predetermined magnetic field is a pulse magnetic field.
Claim 46
Dependent Claim 30 words
A method according to claim 40, wherein the ferroelectric crystal substrate is a C plate substrate which is cut along a face perpendicular to a C axis of a crystal.
Claim 47
Dependent Claim 32 words
A method according to claim 42, wherein the ferroelectric crystal substrate is made of a material selected from a group consisting of LiNb.sub.(1-x) Ta x O 3 (0≦x≦1) and KTiOPO 4 .
Claim 48
Dependent Claim 27 words
A method according to claim 40, further comprising the step of covering at least one of the first electrode and the second electrode with an insulating film.
Claim 49
Dependent Claim 22 words
A method according to claim 40, wherein at least one of the first electrode and the second electrode is a comb-shaped electrode.
Claim 50
Dependent Claim 28 words
A method according to claim 45, further comprising the step of deteriorating ferroelectricity of the ferroelectric crystal substrate in a GaP between electrode branches of the comb-shaped electrode.
Claim 51
Dependent Claim 30 words
A method according to claim 45, further comprising the step of shaving off a surface of the ferroelectric crystal substrate in a gap between electrode branches of the comb-shaped electrode.
Claim 52
Dependent Claim 28 words
A method according to claim 45, further comprising the step of deteriorating ferroelectricity of the ferroelectric crystal substrate in a gap of electrode branches of the comb-shaped electrode.
Claim 53
Dependent Claim 30 words
A method according to claim 45, further comprising the step of shaving off a surface of the ferroelectric crystal substrate in a gap of electrode branches of the comb-shaped electrode.
Claim 54
Dependent Claim 67 words
A method according to claim 40, wherein the ferroelectric crystal substrate is a C plate substrate which is cut along a face perpendicular to a C axis of a crystal, and the first electrode and the second electrode are a comb-shaped electrode formed on a first face of the C plate substrate and a planar electrode formed on a second face of the C plate substrate, respectively.
Claim 55
Dependent Claim 21 words
A method according to claim 50, wherein a nucleus for domain inversion is generated in a vicinity of the first face.
Claim 56
Dependent Claim 32 words
A method according to claim 50, wherein a width of each electrode branch included in the comb-shaped electrode is equal to or smaller than half of an interval between the electrode branches.
Claim 57
Dependent Claim 35 words
A method according to claim 50, further comprising the step of shaving off a surface of the ferroelectric crystal substrate in a vicinity of at least one of the comb-shaped electrode and the planar electrode.
Claim 58
Dependent Claim 27 words
A method according to claim 50, further comprising the step of covering at least one of the comb-shaped electrode and the planar electrode with an insulating film.
Claim 59
Dependent Claim 48 words
A method according to claim 50, wherein the C plate substrate is made of a material selected from a group consisting of LiNb.sub.(1-x) Ta x O 3 (0≦x≦1) and KTiOPO 4 , and the first face is a +C face and the second face is a -C face.
Claim 60
Dependent Claim 64 words
A method according to claim 40, wherein the first electrode is formed on a first face of the ferroelectric crystal substrate and the second electrode is formed on a second face of the ferroelectric crystal substrate which is opposite to the first face, the domain direction of the ferroelectric crystal substrate being perpendicular to the first and second faces of the ferroelectric crystal substrate.
Claim 61
Independent Claim 117 words
A method for manufacturing a domain-inverted region, comprising the steps of: forming a comb-shaped electrode on a first face of a ferroelectric crystal substrate serving as a C plate substrate which is cut along a face perpendicular to a C axis of a crystal; attaching another substrate to the comb-shaped electrode formed on the first face; reducing a thickness of the ferroelectric crystal substrate from a side of a second face which is opposite to the first face; forming a planar electrode on the second face of the ferroelectric crystal substrate; and inverting a domain of a predetermined region in the ferroelectric crystal substrate by applying a predetermined voltage between the comb-shaped electrode and the planar electrode.
Claim 62
Independent Claim 117 words
A method for manufacturing a domain-inverted region, comprising the steps of: forming a comb-shaped electrode on a first face of a ferroelectric crystal substrate serving as a C plate substrate which is cut along a face perpendicular to a C axis of a crystal; attaching another substrate to the comb-shaped electrode formed on the first face; reducing a thickness of the ferroelectric crystal substrate from a side of a second face which is opposite to the first face; forming a planar electrode on the second face of the ferroelectric crystal substrate; and inverting a domain of a predetermined region in the ferroelectric crystal substrate by applying a predetermined voltage between the comb-shaped electrode and the planar electrode.
Claim 63
Dependent Claim 14 words
A method according to claim 57, wherein the predetermined voltage is a pulse voltage.
Claim 64
Dependent Claim 24 words
A method according to claim 57, wherein the predetermined voltage is a combined voltage obtainable by superimposing a pulse voltage on a DC voltage.
Claim 65
Dependent Claim 32 words
A method according to claim 57, wherein the ferroelectric crystal substrate is made of a material selected from a group consisting of LiNb.sub.(1-x) Ta x O 3 (0≦x≦1) and KTiOPO 4 .
Claim 66
Dependent Claim 32 words
A method according to claim 57, wherein a width of each electrode branch included in the comb-shaped electrode is equal to or smaller than half of an interval between the electrode branches.
Claim 67
Dependent Claim 21 words
A method according to claim 57, wherein a nucleus for domain inversion is generated in a vicinity of the first face.
Claim 68
Dependent Claim 28 words
A method according to claim 57, further comprising the step of deteriorating ferroelectricity of the ferroelectric crystal substrate in a gap between electrode branches of the comb-shaped electrode.
Claim 69
Dependent Claim 30 words
A method according to claim 57, further comprising the step of shaving off a surface of the ferroelectric crystal substrate in a gap between electrode branches of the comb-shaped electrode.
Claim 70
Dependent Claim 27 words
A method according to claim 57, further comprising the step of covering at least one of the comb-shaped electrode and the planar electrode with an insulating film.
Claim 71
Independent Claim 103 words
A method for manufacturing a domain-inverted region, comprising the steps of: growing a ferroelectric crystal on a surface of a substrate; forming a first electrode and a second electrode on one of the group consisting of the ferroelectric crystal and the substrate, the first and second electrodes being separated from each other in a domain direction of the ferroelectric crystal; and inverting a domain of a predetermined region in the ferroelectric crystal by applying a predetermined voltage between the first electrode and the second electrode, wherein the predetermined voltage is a combined voltage obtained by superimposing a pulse voltage on a DC voltage.
Claim 72
Independent Claim 103 words
A method for manufacturing a domain-inverted region, comprising the steps of: growing a ferroelectric crystal on a surface of a substrate; forming a first electrode and a second electrode on one of the group consisting of the ferroelectric crystal and the substrate, the first and second electrodes being separated from each other in a domain direction of the ferroelectric crystal; and inverting a domain of a predetermined region in the ferroelectric crystal by applying a predetermined voltage between the first electrode and the second electrode, wherein the predetermined voltage is a combined voltage obtained by superimposing a pulse voltage on a DC voltage.
Claim 73
Dependent Claim 31 words
A method according to claim 66, wherein the ferroelectric crystal is made of a material selected from a group consisting of LiNb.sub.(1-x) Ta x O 3 (0≦x≦1) and KTiOPO 4 .
Claim 74
Dependent Claim 49 words
A method according to claim 66, wherein the ferroelectric crystal grows in a C axis direction, and a comb-shaped electrode and a planar electrode are formed on a surface of the ferroelectric crystal and a bottom face of an optical substrate as the first electrode and the second electrode.
Claim 75
Dependent Claim 24 words
A method according to claim 66, wherein a nucleus for domain inversion is generated in a vicinity of a surface of the ferroelectric crystal.
Claim 76
Dependent Claim 31 words
A method according to claim 66, wherein the domain inverted region in the ferroelectric crystal reaches from the surface on which the electrode is formed to an interface with the substrate.
Claim 77
Dependent Claim 58 words
A method according to claim 66, wherein the first electrode is formed on a surface of the ferroelectric crystal and the second electrode is formed on a bottom surface of the substrate which is opposite to the surface of the ferroelectric crystal, the domain direction of the ferroelectric crystal being perpendicular to the surface of the ferroelectric crystal.
Claim 78
Independent Claim 105 words
A method for manufacturing a domain-inverted region, comprising the steps of: forming a first electrode and a second electrode on a ferroelectric crystal substrate, the first and second electrodes being separated from each other in a domain direction of the ferroelectric crystal substrate; inverting a domain throughout the ferroelectric crystal substrate by applying a first voltage which is opposite to the domain direction between the first electrode and the second electrode; and reinverting the domain in at least part of the ferroelectric crystal substrate by applying a second voltage which is opposite to the inverted domain direction between the first electrode and the second electrode.
Claim 79
Independent Claim 105 words
A method for manufacturing a domain-inverted region, comprising the steps of: forming a first electrode and a second electrode on a ferroelectric crystal substrate, the first and second electrodes being separated from each other in a domain direction of the ferroelectric crystal substrate; inverting a domain throughout the ferroelectric crystal substrate by applying a first voltage which is opposite to the domain direction between the first electrode and the second electrode; and reinverting the domain in at least part of the ferroelectric crystal substrate by applying a second voltage which is opposite to the inverted domain direction between the first electrode and the second electrode.
Claim 80
Dependent Claim 19 words
A method according to claim 72, wherein the first voltage and the second voltage are applied at room temperature.
Claim 81
Dependent Claim 14 words
A method according to claim 72, wherein the first voltage is a pulse voltage.
Claim 82
Dependent Claim 24 words
A method according to claim 72, wherein the first voltage is a combined voltage obtainable by superimposing a pulse voltage on a DC voltage.
Claim 83
Dependent Claim 32 words
A method according to claim 72, wherein the ferroelectric crystal substrate is made of a material selected from a group consisting of LiNb.sub.(1-x) Ta x O 3 (0≦x≦1) and KTiOPO 4 .
Claim 84
Dependent Claim 27 words
A method according to claim 72, further comprising the step of covering at least one of the first electrode and the second electrode with an insulating film.
Claim 85
Dependent Claim 64 words
A method according to claim 72, wherein the first electrode is formed on a first face of the ferroelectric crystal substrate and the second electrode is formed on a second face of the ferroelectric crystal substrate which is opposite to the first face, the domain direction of the ferroelectric crystal substrate being perpendicular to the first and second faces of the ferroelectric crystal substrate.

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