US4073675A
Expired / Lapsed
US
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Waveguiding epitaxial LiNbO3 films
Assignee: AT&T Inc
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Filing: 1976-07-21
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Granted: 1978-02-14
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Expires: 1996-07-21
Abstract
Abstract A process is described for making optical circuits on LiTaO 3 substrates. The process involves putting down an epitaxial layer of LiNbO 3 on the LiTaO 3 substrates. Growth is preferably carried out on certain planes of the LiTaO 3 . These optical circuits are unique in that they are smooth, uniform in thickness and have a refractive index significantly larger than that of the substrate. This is advantageous in optical circuitry, since the optical modes in the circuits are quite distinct and can be coupled separately using such light sources as lasers and light emitting diodes.
Inventors
- 👤 Albert A. Ballman
- 👤 Harold Brown
- 👤 Raymond J. Martin
- 👤 Ping K. Tien
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 13:47
CPC Classifications
C; C30; C30B; C30B19/00; C30B11/00; C30B29/00; C30B29/10; C30B29/16; C30B29/22; C30B29/30; Y; Y10; Y10S; Y10S117/00; Y10S117/918
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
150 words
A process for producing epitaxial crystalline films of LiNbO 3 on LiTaO 3 substrates in which the films are grown on a crystallographic plane of LiTaO 3 selected from the group consisting of the 10.2, 11.2, 01.2, 10.2, 01.2 and 11.2 planes comprising the steps of: a. preparing the LiNbO 3 in the form of a powder with particle size less than 50 microns, b. preparing a suspension of LiNbO 3 in a viscous liquid organic medium which evaporates or decomposes on heating, c. spreading some of the suspension of LiNbO 3 on the LiTaO 3 substrate, d. heating the LiTaO 3 substrate to a temperature between 1260° and 1320° C, e. maintaining the temperature of the LiTaO 3 substrate between 1260° and 1320° C for from 1 minute to 2 hours, f. cooling the LiTaO 3 substrate at a rate of 10°-50° C per hour to below 600° C.
Claim 2
Dependent Claim
150 words
A process for producing epitaxial crystalline films of LiNbO 3 on LiTaO 3 substrates in which the films are grown on a crystallographic plane of LiTaO 3 selected from the group consisting of the 10.2, 11.2, 01.2, 10.2, 01.2 and 11.2 planes comprising the steps of: a. preparing the LiNbO 3 in the form of a powder with particle size less than 50 microns, b. preparing a suspension of LiNbO 3 in a viscous liquid organic medium which evaporates or decomposes on heating, c. spreading some of the suspension of LiNbO 3 on the LiTaO 3 substrate, d. heating the LiTaO 3 substrate to a temperature between 1260° and 1320° C, e. maintaining the temperature of the LiTaO 3 substrate between 1260° and 1320° C for from 1 minute to 2 hours, f. cooling the LiTaO 3 substrate at a rate of 10°-50° C per hour to below 600° C.
Claim 3
Dependent Claim
19 words
The process of claim 1 in which the viscous liquid organic medium has a viscosity of at last 800.
Claim 4
Dependent Claim
13 words
The process of claim 2 in which viscous organic medium is a lacquer.
Claim 5
Dependent Claim
16 words
The process of claim 1 in which the particle size is between 25 and 50 microns.
Claim 6
Dependent Claim
17 words
The process of claim 1 in which the cooling is between 15° and 30° C per hour.
Claim 7
Dependent Claim
155 words
A process for producing epitaxial crystalline films of LiNbO 3 on LiTaO 3 substrates in which the films are grown on a crystallographic plane of LiTaO 3 selected from the group consisting of the 10.2, 11.2, 01.2, 10.2, 01.2 and 11.2 planes comprising the steps of: a. preparing the LiNbO 3 in the form of a powder with particle size less than 50 microns, b. distributing some LiNbO 3 powder on the surface of the LiTaO 3 substrate, c. placing a platinum foil on top of the LiNbO 3 powder on the LiTaO 3 substrate, d. applying a pressure of 1-20 gms/cm 2 to the platinum sheet, e. maintaining the temperature of the LiTaO 3 substrate between 1260° and 1320° C for from 1 minute to 2 hours, f. cooling the LiTaO 3 substrate at a rate of 10°-50° C per hour to below 600° C and then to room temperature, removing the platinum foil.
Claim 8
Dependent Claim
155 words
A process for producing epitaxial crystalline films of LiNbO 3 on LiTaO 3 substrates in which the films are grown on a crystallographic plane of LiTaO 3 selected from the group consisting of the 10.2, 11.2, 01.2, 10.2, 01.2 and 11.2 planes comprising the steps of: a. preparing the LiNbO 3 in the form of a powder with particle size less than 50 microns, b. distributing some LiNbO 3 powder on the surface of the LiTaO 3 substrate, c. placing a platinum foil on top of the LiNbO 3 powder on the LiTaO 3 substrate, d. applying a pressure of 1-20 gms/cm 2 to the platinum sheet, e. maintaining the temperature of the LiTaO 3 substrate between 1260° and 1320° C for from 1 minute to 2 hours, f. cooling the LiTaO 3 substrate at a rate of 10°-50° C per hour to below 600° C and then to room temperature, removing the platinum foil.
Claim 9
Dependent Claim
16 words
The process of claim 1 in which the particle size is between 25 and 50 microns.
Claim 10
Dependent Claim
17 words
The process of claim 1 in which the cooling is between 15° and 30° C per hour.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1981-02-13 | 1981-08-15 | 1982-02-14 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1985-02-13 | 1985-08-15 | 1986-02-14 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1989-02-13 | 1989-08-15 | 1990-02-14 | $7700.00 | Window Closed / Lapsed |