US4938836A
Expired / Lapsed
US
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Process for locally increasing the refractive indexes of an electrooptical material usable in guided optics and material obtained by this process
Assignee: Ministère des Postes Télégraphes et Téléphones
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Filing: 1988-03-23
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Granted: 1990-07-03
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Expires: 2008-03-23
Abstract
Abstract Process for locally increasing the refractive indexes of an electrooptical material usable in guided optics and material obtained by this process. The process according to the invention consists of carrying out an implantation of ions (6) of sulphur or a metallic dopant able to take the place of a cation of the crystal lattice of the ferroelectric material (2), followed by annealing at between 300° and 600° C. in order to rearrange the crystal lattice disturbed during implantation and for activating the implanted ions. Ion implantation is carried out in an inclined direction (60) with respect to the normal to the surface of the monocrystalline material (2). For a LiNbO 3 monocrystal, use is made of Ti ions as the dopant. This process makes it possible to produce a guide layer (4) having ordinary and extraordinary refractive indices above those of the pure monocrystal.
Inventors
- 👤 Alain Carenco
- 👤 Elchuri Rao
- 👤 Sylvie Fouchet
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 09:02
CPC Classifications
C; C30; C30B; C30B31/00; C30B31/20; C30B31/22; G; G02; G02B; G02B6/00; G02B6/10; G02B6/12; G02B6/122; G02B6/125; G02B6/13; G02B6/134; G02B6/1347; Y; Y10; Y10S; Y10S117/00; Y10S117/906
Claims Analysis
Total Claims: 19
Claim 1
Independent Claim
155 words
A process for producing an optical waveguide into the surface of a ferroelectric monocrystalline material, comprising essentially at least one ion implantation of sulfur or a metallic dopant liable to take the place of a cation of the crystal lattice of the material, said implantation taking place in vacuum and at the surface of said material at an inclined direction with respect to the normal to the surface of said material, and an annealing of the implanted material at a temperature from 300° to 600° C. in an oxygen atmosphere in order to rearrange the crystal lattice disturbed during implantation and to activate the implanted ions, while preventing the diffusion thereof into the material, in order to obtain an index hopping surface wave-guide which is thermally stable and has a surface implanted guide layer having ordinary and extraordinary positive refractive indexes respectively higher than the positive ordinary and extraordinary refractive indexes of the non-implanted material.
Claim 2
Dependent Claim
155 words
A process for producing an optical waveguide into the surface of a ferroelectric monocrystalline material, comprising essentially at least one ion implantation of sulfur or a metallic dopant liable to take the place of a cation of the crystal lattice of the material, said implantation taking place in vacuum and at the surface of said material at an inclined direction with respect to the normal to the surface of said material, and an annealing of the implanted material at a temperature from 300° to 600° C. in an oxygen atmosphere in order to rearrange the crystal lattice disturbed during implantation and to activate the implanted ions, while preventing the diffusion thereof into the material, in order to obtain an index hopping surface wave-guide which is thermally stable and has a surface implanted guide layer having ordinary and extraordinary positive refractive indexes respectively higher than the positive ordinary and extraordinary refractive indexes of the non-implanted material.
Claim 3
Dependent Claim
31 words
The process according to claim 1, characterized in that there are at least two successive implantations of said dopant at different doses and energies in order to form the optical waveguide.
Claim 4
Dependent Claim
15 words
The process according to claim 1, characterized in that the inclination is close to 7°.
Claim 5
Dependent Claim
35 words
The process according to claim 1, characterized in that the material is chosen from the group consisting of lithium niobate, lithium tantalate, barium titanate, strontium and barium niobate, potassium niobate and barium and sodium niobate.
Claim 6
Dependent Claim
19 words
The process according to claim 4, characterized in that the metallic dopant is an ion of a transition metal.
Claim 7
Dependent Claim
33 words
The process according to claim 4, characterized in that the metallic dopant is chosen from the group consisting of titanium, vanadium, nickel, iron, cobalt, silver, gold, niobium, tantalum, chromium, copper, zinc and zirconium.
Claim 8
Dependent Claim
22 words
The process according to claim 1, characterized in that the material is lithium niobate or lithium tantalate and the dopant is titanium.
Claim 9
Dependent Claim
19 words
The process according to claim 1, characterized in that the implantation energies are between 100 keV and 2 MeV.
Claim 10
Dependent Claim
26 words
The process according to claim 1, characterized in that the ion implantation dose is in the range from 5·10 15 to 5·10 16 ions/cm 2 .
Claim 11
Dependent Claim
24 words
The process according to claim 1, characterized in that there are at least two successive implantations of said dopant at different doses and energies.
Claim 12
Dependent Claim
179 words
A process for producing an optical wave-guide into the surface of a ferroelectric monocrystalline material selected from the group consisting of lithium niobate, lithium tantalate, barium titanate, strontium and barium niobate, potassium niobate and barium and sodium niobate, comprising essentially at least one ion implantation of a transition metal dopant liable to take the place of a cation of the crystal lattice of the material, said implantation taking place in vacuum and at the surface of said material at an inclined direction with respect to the normal to the surface of said material, and an annealing of the implanted material at a temperature from 300° to 600° C. in an oxygen atmosphere in order to rearrange the crystal lattice disturbed during implantation and to activate the implanted ions, while preventing the diffusion thereof into the material and outdiffusion, in order to obtain an index hopping surface wave-guide which is thermally stable and has a surface implanted guide layer having ordinary and extraordinary positive refractive indexes respectively higher than the positive ordinary and extraordinary refractive indexes of the non-implanted material.
Claim 13
Dependent Claim
179 words
A process for producing an optical wave-guide into the surface of a ferroelectric monocrystalline material selected from the group consisting of lithium niobate, lithium tantalate, barium titanate, strontium and barium niobate, potassium niobate and barium and sodium niobate, comprising essentially at least one ion implantation of a transition metal dopant liable to take the place of a cation of the crystal lattice of the material, said implantation taking place in vacuum and at the surface of said material at an inclined direction with respect to the normal to the surface of said material, and an annealing of the implanted material at a temperature from 300° to 600° C. in an oxygen atmosphere in order to rearrange the crystal lattice disturbed during implantation and to activate the implanted ions, while preventing the diffusion thereof into the material and outdiffusion, in order to obtain an index hopping surface wave-guide which is thermally stable and has a surface implanted guide layer having ordinary and extraordinary positive refractive indexes respectively higher than the positive ordinary and extraordinary refractive indexes of the non-implanted material.
Claim 14
Dependent Claim
33 words
The process according to claim 11, characterized in that the metallic dopant is chosen from the group consisting of titanium, vanadium, nickel, iron, cobalt, silver, gold, niobium, tantalum, chromium, copper, zinc and zirconium.
Claim 15
Dependent Claim
22 words
The process according to claim 11, characterized in that the material is lithium niobate or lithium tantalate and the dopant is titanium.
Claim 16
Dependent Claim
15 words
The process according to claim 11, characterized in that the inclination is close to 7°.
Claim 17
Dependent Claim
24 words
The process according to claim 11, characterized in that there are at least two successive implantations of said dopant at different doses and energies.
Claim 18
Dependent Claim
19 words
The process according to claim 11, characterized in that the implantation energies are between 100 keV and 2 MeV.
Claim 19
Dependent Claim
22 words
The process according to claim 11, characterized in that said implantation doses vary from 5·10 15 to 5·10 16 ions/cm 2 .
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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) | 1993-07-02 | 1994-01-01 | 1994-07-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1997-07-02 | 1998-01-01 | 1998-07-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2001-07-02 | 2002-01-01 | 2002-07-03 | $7700.00 | Window Closed / Lapsed |