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US5209917A
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Lithium niobate single crystal thin film and production method thereof
Assignee: Ibiden Co Ltd
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Filing: 1990-09-20
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Granted: 1993-05-11
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Expires: 2010-09-20
Abstract
Abstract A lithium niobate single crystal thin film formed on a lithium tantalate substrate, in which the a-axis lattice constant of the lithium tantalate substrate and the a-axis lattice constant of the lithium niobate single crystal thin film are lattice matched. To achieve the lattice matching, the lithium tantalate substrate is contacted with a molten composition to epitaxially grow a lithium niobate single crystal thin film, the molten composition mainly comprising Li 2 O, V 2 O 5 , Nb 2 O 5 , Na 2 O and MgO, whereby the a-axis lattice constant of the lithium niobate single crystal thin film and the a-axis lattice constant of the lithium tantalate substrate are matched to each other. With this arrangement, a lithium niobate single crystal thin film with large thickness and low propagation loss can be obtained without poling, which could not be obtained with prior art methods, thus greatly contributing to the optical device industry.
Inventors
- 👤 Satoshi Ohno
- 👤 Ryo Enomoto
- 👤 Masaya Yamada
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 22:01
CPC Classifications
G; G02; G02B; G02B6/00; G02B6/10; G02B6/12; G02B6/13; C; C30; C30B; C30B19/00; C30B19/02; C30B19/04; C30B29/00; C30B29/10; C30B29/16; C30B29/22; C30B29/30; Y; Y10; Y10S; Y10S117/00; Y10S117/918
Claims Analysis
Total Claims: 21
Claim 1
Independent Claim
78 words
A lithium niobate single crystal thin film formed on a lithium tantalate substrate, characterized in that said lithium niobate single crystal thin film is formed on a (0001) surface of said lithium tantalate substrate, the a-axis lattice constant of said lithium niobate single crystal thin film is 99.81 to 100.07% of the a-axis lattice constant of said lithium tantalate substrate, and said lithium niobate single crystal thin film has an optical propagation loss of 1.4 dB/cm or less.
Claim 2
Dependent Claim
78 words
A lithium niobate single crystal thin film formed on a lithium tantalate substrate, characterized in that said lithium niobate single crystal thin film is formed on a (0001) surface of said lithium tantalate substrate, the a-axis lattice constant of said lithium niobate single crystal thin film is 99.81 to 100.07% of the a-axis lattice constant of said lithium tantalate substrate, and said lithium niobate single crystal thin film has an optical propagation loss of 1.4 dB/cm or less.
Claim 3
Dependent Claim
25 words
The lithium niobate single crystal thin film of claim 1 wherein an a-axis lattice constant of said lithium tantalate substrate is 5.128 to 5.173 angstroms.
Claim 4
Dependent Claim
26 words
The lithium niobate single crystal thin film of claim 1 wherein said lithium tantalate substrates contains a different element at least in part of its surface.
Claim 5
Dependent Claim
39 words
The lithium niobate single crystal thin film of claim 3 wherein said different element is at least one selected from the group consisting of magnesium (Mg), titanium (Ti), vanadium (V), chromium (Cr), iron (Fe), nickel (Ni), and neodymium (Nd).
Claim 6
Dependent Claim
12 words
The lithium niobate single crystal thin film of claim 1 containing sodium.
Claim 7
Dependent Claim
21 words
The lithium niobate single crystal thin film of claim 5 wherein the content of sodium is 0.1 to 14.3 mole %.
Claim 8
Dependent Claim
12 words
The lithium niobate single crystal thin film of claim 1 containing magnesium.
Claim 9
Dependent Claim
21 words
The lithium niobate single crystal thin film of claim 7 wherein the content of magnesium is 0.8 to 10.8 mole %.
Claim 10
Dependent Claim
34 words
The lithium niobate single crystal thin film of claim 1 containing at least one element selected from the group consisting of neodymium (Nd), rhodium (Rh), zinc (Zn), nickel (Ni), cobalt (Co), and titanium (Ti).
Claim 11
Independent Claim
88 words
A method for producing a lithium niobate single crystal thin film comprising contacting a lithium tantalate substrate with a molten composition to epitaxially grow a lithium niobate single crystal thin film, said molten composition comprising Li 2 O, V 2 O 5 , Nb 2 O 5 , Na 2 O and M g O, thereby growing said lithium niobate single crystal thin film having an a-axis lattice constant of 99.81 to 100.07% that of said lithium tantalate substrate on a (0001) surface of said lithium tantalate substrate.
Claim 12
Independent Claim
88 words
A method for producing a lithium niobate single crystal thin film comprising contacting a lithium tantalate substrate with a molten composition to epitaxially grow a lithium niobate single crystal thin film, said molten composition comprising Li 2 O, V 2 O 5 , Nb 2 O 5 , Na 2 O and M g O, thereby growing said lithium niobate single crystal thin film having an a-axis lattice constant of 99.81 to 100.07% that of said lithium tantalate substrate on a (0001) surface of said lithium tantalate substrate.
Claim 13
Dependent Claim
31 words
The method for producing a lithium niobate single crystal thin film of claim 10 wherein the a-axis lattice constant of said lithium tantalate substrate is adjusted to 5.128 to 5.173 angstroms.
Claim 14
Dependent Claim
35 words
The method for producing a lithium niobate single crystal thin film of claim 10 wherein said lithium tantalate substrate is a lithium niobate single crystal substrate formed with a lithium tantalate single crystal thin film.
Claim 15
Dependent Claim
31 words
The method for producing a lithium niobate single crystal thin film of claim 10 wherein said lithium tantalate substrate is added a different element at least in part of its surface.
Claim 16
Dependent Claim
38 words
The method for producing a lithium niobate single crystal thin film of claim 10 wherein the method of adding said different element is selected from thermal diffusion, ion exchange, ion implantation, liquid phase epitaxy, and raw material addition.
Claim 17
Dependent Claim
80 words
The method for producing a lithium niobate single crystal thin film of claim 10 wherein said molten composition is in a compositional range of Li 2 O, V 2 O 5 , and Nb 2 O 5 within the area surrounded by five compositional points A(88.90, 2.22, 8.88), B(55.00, 43.00, 2.00), C(46.50, 51.50, 2.00), D(11.11, 80.00, 8.89), and E(37.50, 5.00, 57.50) in a triangular diagram of ternary system of Li 2 O-V 2 O 5 -Nb 2 O 5 .
Claim 18
Dependent Claim
27 words
The method for producing a lithium niobate single crystal thin film of claim 10 wherein the Na 2 O/Li 2 O molar ratio is 2.0/98.0 to 93.5/6.5.
Claim 19
Dependent Claim
24 words
The method for producing a lithium niobate single crystal thin film of claim 10 wherein the MgO/lithium niobate molar ratio is 0.1/99.9 to 25.0/75.0.
Claim 20
Dependent Claim
44 words
The method for producing a lithium niobate single crystal thin film of claim 10 wherein said molten composition contains at least one oxide selected from the group consisting of oxides of neodymium (Nd), rhodium (Rh), zinc (Zn), nickel (Ni), cobalt (Co), and titanium (Ti).
Claim 21
Dependent Claim
32 words
The method for producing a lithium niobate single crystal thin film of claim 10 wherein said lithium niobate single crystal thin film is grown at a temperature of 600° to 1,250° C.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1996-05-10 | 1996-11-09 | 1997-05-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2000-05-10 | 2000-11-09 | 2001-05-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2004-05-10 | 2004-11-09 | 2005-05-11 | $7700.00 | Window Closed / Lapsed |