Planar optical waveguide and method of manufacturing same

• US 4,712,855 A
• Filed: 01/13/1986
• Issued: 12/15/1987
• Est. Priority Date: 04/20/1985
• Status: Expired due to Fees

• Current Assignee: US Philips Corporation (Koninklijke Philips N.V.)
• Original Assignee: US Philips Corporation (Koninklijke Philips N.V.)
• Inventors: Klages, Claus-Peter, Pross, Elke B., Tolksdorf, Wolfgang F. M., Dammann, Hans O. B., Bartels, Inske E. H.
• Primary Examiner(s): Sikes, William L.
• Assistant Examiner(s): Ullah, Akm E.
• Application Number:
  US06/818,152
• Time in Patent Office: 701 Days
• Field of Search: 350/96.11, 350/96.12, 350/96.13, 350/96.14, 350/96.30, 350/96.34
• US Class Current: 385/129
• CPC Class Codes: B82Y 25/00 Nanomagnetism, e.g. magnetoimpedance, anisotropic magnetoresistance, giant magnetoresistance or tunneling magnetoresistance
• CPC Class Codes: G02F 1/095 in an optical waveguide structure
• CPC Class Codes: H01F 10/245 Modifications for enhancing interaction with electromagnetic wave energy
• CPC Class Codes: H01F 10/3209 Exchange coupling of garnet multilayers

Abstract

Planar optical waveguide having a crystal body consisting of a nonmagnetic substrate having a first magnetooptical layer epitaxially provided on the substrate and a second magnetooptical layer epitaxially provided on the first mangetooptical layer. The two magnetooptical layers consist of a material based on iron garnet. The second magnetooptical layer has a refractice index n₂ which is approximately 1×10^-3 to 1×10^-2 higher than the refractive index n₁ of the first magnetooptical layer. A layer of a material based on iron garnet and absorbing radiation in the wavelength range of 1.0≦λ≦2.5 μm is provided between the substrate and the first magnetooptical layer, said iron garnet-based layer having a refractive index n_A which is higher than the refractive index of the first magnetooptical layer.

Claims

1. A planar optical waveguide having a crystal body consisting of a nonmagnetic substrate having a first magnetooptical layer epitaxially provided on the substrate and a second magnetooptical layer epitaxially provided on the first magnetooptical layer, the two magnetooptical layers consisting of a material based on iron garnet, the second magnetooptical layer having a refractive index n₂ which is approximately 1×

10^-3 to 1×

10^-2 higher than the refractive index n₁ of the first magnetooptical layer;

characterized in that a layer (5) of a material based on iron garnet and absorbing radiation in the wavelength of 1.0≦

λ

≦

2.5 μ

m is provided between the substrate (3) and the first magnetooptical layer (7), said iron garnet-based layer having a refractive index n_A which is higher than the refractive index of the first magnetooptical layer.

2. A planar optical waveguide as claimed in claim 1, characterized in that the material for the magnetooptical layers has as composition defined by the general formula Y_3-x Pb_x Fe₅ O₁₂ where x=0.007 to 0.025 for the first magnetooptical layer (7) adjoining the absorption layer (5) and where x=0.02 to 0.04 for the second magnetooptical layer (9) provided on the first magnetooptical layer.

3. A planar optical waveguide as claimed in claim 2, characterized in that in the material of the absorption layer (5) at least a substituent in the form of a cation which can occupy dodecahedral, octahedral or tetrahedral lattice sites is present in the garnet lattice.

4. A planar optical waveguide as claimed in claim 3, characterized in that the absorption layer (5) has a composition defined by the general formula Y₃ Fe_5-x-y-z A_x D_y M_z O₁₂ in which

A=Co^III,

D=Co^III,

M=Si^IV, Ge^IV, Ti^IV, Zr^IV or mixtures of these ions where

0≦

x≦

0.3

0≦

y≦

0.3

z≧

y

0≦

y+z≦

0.6

x+y+z≦

0.6

x+y>

0

and where z=0 when y=0.

5. A planar optical waveguide as claimed in claim 4, characterized in that the absorption layer (5) has a composition defined by the formula Y₃ Fe₄.9 Co₀.1 O₁₂.

6. A planar optical waveguide as claimed in claim 4, characterized in that the absorption layer (5) has a composition defined by the formula Y₃ Fe₄.939 Co₀.018 Ge₀.042 O₁₂.

7. A planar optical waveguide as claimed in claim 4, characterized in that the absorption layer (5) has a composition defined by the formula Y₃ Fe₄.73 Co₀.12 Si₀.15 O₁₂.

8. A planar optical waveguide as claimed in claim 4 characterized in that the absorption layer (5) has a thickness of ≦

100 μ

m.

9. A planar optical waveguide as claimed in claim 4, characterized in that the substrate (3) has a composition defined by the formula Gd₃ Ga₅ O₁₂.

10. A planar optical waveguide comprising:

a nonmagnetic substrate;

an absorption layer epitaxially provided on the substrate, said absorption layer being an iron garnet, said absorption layer absorbing radiation in the wavelength range from 1.0 to 2.5 microns, said absorption layer having a refractive index n_A ;

a first magnetooptical layer epitaxially provided on the absorption layer, said first magnetooptical layer being an iron garnet, said first magnetooptical layer having a refractive index n₁ which is less than n_A ; and

a second magnetooptical layer epitaxially provided on the first magnetooptical layer, said second magnetooptical layer being an iron garnet, said second magnetooptical layer having a refractive index n₂ which is approximately 1×

10^-3 to 1×

10^-2 times greater than n₁.

11. A planar optical waveguide as claimed in claim 10, characterized in that the waveguide is a single mode waveguide.

16. A method as claimed in claim 11, characterized in that an absorption layer defined by the formula Y₃ Fe₄.9 Co₀.1 O₁₂ is deposited on the substrate.

17. A method as claimed in claim 11, characterized in that an absorption layer defined by the formula Y₃ Fe₄.939 Co₀.018 Ge₀.042 O₁₂ is deposited on the substrate.

18. A method as claimed in claim 11, characterized in that an absorption layer defined by the formula Y₃ Fe₄.73 Co₀.12 Si₀.15 O₁₂ is deposited on the substrate.

19. A method as claimed in claim 11, characterized in that a substrate of the composition Gd₃ Ga₅ O₁₂ is used.

12. A planar one-way optical waveguide comprising:

a nonmagnetic substrate;

an absorption layer epitaxially provided on the substrate, said absorption layer being an iron garnet, said absorption layer absorbing radation in the wavelength range from 1.0 to 2.5 microns, said absorption layer having a refractive index n_A ;

a first magnetooptical layer epitaxially provided on the absorption layer, said first magnetooptical layer being an iron garnet, said first magnetooptical layer having a refractive index n₁ which is less than n_A ; and

a second magnetooptical layer epitaxially provided on the first magnetooptical layer, said second magnetooptical layer being an iron garnet, said second magnetooptical layer having a refractive index n₂ which is approximately 1×

10^-3 to 1×

10^-2 times greater than n₁.

13. A planar optical waveguide as claimed in claim 12, characterized in that the waveguide is a single mode waveguide.

20. A method as claimed in claim 12, characterized in that the waveguide is a single mode waveguide.

14. A method of manufacturing a planar optical waveguide, said method comprising the steps of:

providing a nonmagnetic substrate;

epitaxially depositing an absorption layer on the substrate, said absorption layer being an iron garnet, said absorption layer absorbing radiation in the wavelength range from 1.0 to 2.5 microns, said absorption layer having a refractive index n_A ;

epitaxially depositing a first magnetooptical layer on the absorption layer, said first magnetooptical layer being an iron garnet, said first magnetooptical layer having a refractive index n₁ which is less than n_A ; and

epitaxially depositing a second magnetooptical layer on the first magnetooptical layer, said second magnetooptical layer being an iron garnet, said second magnetooptical layer having a refractive index n₂ which is approximately 1×

10^-3 to 1×

10^-2 times greater than n₁.

15. A method as claimed in claim 14, characterized in that an absorption layer having a composition defined by the general formula Y₃ Fe_5-x-y-z A_x D_y M_z O₁₂ is deposited on the substrate, in which

A=Co^III,

D=Co^II,

M=Si^IV, Ge_IV, Ti^IV, Zr^IV or mixtures of these ions,

where

0≦

x≦

0.3

0≦

y≦

0.3

z≧

y

0≦

y+z≦

0.6

x+y+z≦

0.6

x+y>

0

and where z=0 when y=0.