Optical isolator

• US 5,661,829 A
• Filed: 03/19/1996
• Issued: 08/26/1997
• Est. Priority Date: 03/19/1996
• Status: Expired due to Term

• Current Assignee: Oplink Communications
• Original Assignee: Oplink Communications
• Inventors: Zheng, Yu
• Primary Examiner(s): Ullah, Akm E.
• Application Number:
  US08/618,189
• Time in Patent Office: 525 Days
• Field of Search: 385/11, 385/31-35, 385/16, 385/123, 385/130, 359/497, 359/119, 359/501, 356/358, 356/375, 356/345, 356/369, 250/227.19, 348/25, 348/61, 348/273, 348/335, 348/340, 348/571
• US Class Current: 385/33
• CPC Class Codes: G02B 6/2746 comprising non-reciprocal devices, e.g. isolators, FRM, circulators, quasi-isolators magneto-optic non-reciprocal devices G02F1/093
• CPC Class Codes: G02F 1/093 used as non-reciprocal devices, e.g. optical isolators, circulators G02F1/0955 takes precedence

Abstract

A system and method for providing an optical isolator comprising a first collimating means, a core, and a second collimating means is disclosed. The first collimating means comprises at least a first optical fiber holder, a first lens, and a first collimator holder. The core comprises a first polarizer, a polarization rotation means, and a second polarizer. The second collimating means comprises at least a second optical fiber holder, a second lens, and a second collimator holder. One aspect of the method and system provides a quartz collimator aligner in a collimating means. The quartz collimator aligner aligns the optical fiber holder and the lens. The collimator holder is disposed around the quartz collimating aligner. The quartz collimator aligners improve the alignment of the collimator, thereby reducing insertion loss. The smoothness quartz collimator aligners also increases return loss. Another aspect of the method and system provides a core assembly holder in which the polarization rotation means is disposed. This embodiment increases the ability to adjust the orientation of the first and second polarizers.

Claims

1. An optical isolator comprising:

a first collimating means, the first collimating means further comprising

a first optical fiber holder,

a first lens located opposite to the first optical fiber holder,

a first quartz collimator aligner for aligning the first optical fiber holder and the first lens,

a first collimator holder disposed around the first quartz collimator aligner;

a core, the core further comprising

a first polarizer,

a second polarizer, and

a polarization rotation means located between the first polarizer and the second polarizer; and

a second collimating means, the second collimating means further comprising

a second optical fiber holder,

a second lens located opposite to the optical fiber holder,

a second quartz collimator aligner for aligning the second optical fiber holder and the second lens, and

a second collimator holder disposed around the second quartz collimator aligner.

2. The optical isolator of claim 1 wherein the first quartz collimator aligner has an aperture therein, the first optical fiber holder and the first lens being disposed in the aperture in the first quartz collimator aligner;

and

the second quartz collimator aligner has an aperture therein, the second optical fiber holder and the second lens being disposed in the aperture in the second quartz collimator aligner.

3. The optical isolator of claim 1 wherein the first optical fiber holder comprises a microcapillary;

and the second optical fiber holder comprises a microcapillary.

4. The optical isolator of claim 3 wherein the polarization rotation means comprises a faraday rotator.

6. The optical isolator of claim 1 wherein the core further comprises a core assembly holder located between the first polarizer and the second polarizer;

the polarization rotation means being disposed in the core assembly holder.

8. The optical isolator of claim 1 wherein the core further comprises a core holder disposed around the first polarizer, the polarization rotation means, and the second polarizer, the core holder having at least one aperture therein;

and

wherein the optical isolator further comprises a plurality of solder joints connecting the second collimator holder to the core holder, each of a portion of the plurality of solder joints being at least partially disposed in each of the at least one aperture in the core holder.

10. The optical isolator of claim 6 wherein the core further comprises a core holder disposed around the first polarizer, the polarization rotation means, and the second polarizer, the core holder having at least one aperture therein;

and

wherein the optical isolator further comprises a plurality of solder joints connecting the second collimator holder to the core holder, each of a portion of the plurality of solder joints being at least partially disposed in each of the at least one aperture in the core holder.

15. The optical isolator of claim 8 wherein at least a second portion of the solder joints are flux-less solder joints.

16. The optical isolator of claim 15 wherein a portion of the second collimator holder comprises brass;

and wherein the flux-less solder joints further comprise solder and gold plating.

17. The optical isolator of claim 16 wherein the gold plating is 90 micrometers thick.

18. The optical isolator of claim 17 wherein the solder is Sn63Pb37.

23. The optical isolator of claim 10 wherein at least a second portion of the solder joints are flux-less solder joints.

24. The optical isolator of claim 23 wherein a portion of the second collimator holder comprises brass;

and wherein the flux-less solder joints further comprise solder and gold plating.

25. The optical isolator of claim 24 wherein the gold plating is 90 micrometers thick.

26. The optical isolator of claim 25 wherein the solder is Sn63Pb37.

5. An optical isolator comprising:

a first collimating means, the first collimating means further comprising

a first optical fiber holder, and

a first lens located opposite to the first optical fiber holder;

a core, the core further comprising

a first polarizer,

a second polarizer

a core assembly holder located between the first polarizer and the second polarizer, and

polarization rotation means disposed in the core assembly holder; and

a second collimating means, the second collimating means further comprising

a second optical fiber holder, and

a second lens located opposite to the second optical fiber holder.

9. The optical isolator of claim 5 wherein

the second collimating means further comprises a second collimator holder;

the core further comprises a core holder disposed around the first polarizer, the polarization rotation means, and the second polarizer, the core holder having at least one aperture therein; and

the optical isolator further comprises a plurality of solder joints connecting the second collimator holder to the core holder, each of a portion of the plurality of solder joints being at least partially disposed in each of the at least one aperture in the core holder.

19. The optical isolator of claim 9 wherein at least a second portion of the solder joints are flux-less solder joints.

20. The optical isolator of claim 19 wherein a portion of the second collimator holder comprises brass;

and wherein the flux-less solder joints further comprise solder and gold plating.

21. The optical isolator of claim 20 wherein the gold plating is 90 micrometers thick.

22. The optical isolator of claim 21 wherein the solder is Sn63Pb37.

7. An optical isolator comprising:

a first collimating means, the first collimating means further comprising

a first optical fiber holder, and

a first lens located opposite to the first optical fiber holder;

a core, the core further comprising

a first polarizer,

a second polarizer,

a polarization rotation means located between the first polarizer and the second polarizer, and

a core holder disposed around the first polarizer, the polarization rotation means, and the second polarizer, the core holder having at least one aperture therein;

a second collimating means, the second collimating means further comprising

a second optical fiber holder,

a second lens located opposite to the second optical fiber holder, and

a second collimator holder disposed around the second optical fiber holder and the second lens; and

a plurality of solder joints connecting the second collimator holder to the core holder, each of a portion of the plurality of solder joints being at least partially disposed in each of the at least one aperture in the core holder.

11. The optical isolator of claim 7 wherein at least a second portion of the solder joints are flux-less solder joints.

12. The optical isolator of claim 11 wherein a portion of the second collimator holder comprises brass;

and wherein the flux-less solder joints further comprise solder and gold plating.

13. The optical isolator of claim 12 wherein the gold plating is 90 micrometers thick.

14. The optical isolator of claim 13 wherein the solder is Sn63Pb37.

27. A method for producing an optical isolator, the method comprising the steps of:

providing a first collimating means, the step of providing a first collimating means further comprising the steps of;

providing a first optical fiber holder,

providing a first lens located opposite to the first optical fiber holder,

providing a first quartz collimator aligner for aligning the first optical fiber holder and the first lens, and

providing a first collimator holder disposed around the first quartz collimator aligner;

providing a core, the step of providing a core further comprising the steps of

providing a first polarizer,

providing a second polarizer, and

providing a polarization rotation means located between the first polarizer and the second polarizer; and

providing a second collimating means, the step or providing a second collimating means further comprising the steps of

providing a second optical fiber holder, and

providing a second lens located opposite to the second optical fiber holder.

28. The method of claim 27 wherein the step of providing a first quartz collimator holder further comprises the steps of:

providing a first quartz collimator holder having an aperture therein; and

locating the first optical fiber holder and the first lens within the aperture in the first quartz collimator holder.

29. The method of claim 28 wherein the step of providing the second collimating means further comprises the steps of:

providing a second quartz collimator aligner for aligning the second optical fiber holder and the second lens; and

providing a second collimator holder disposed around the second quartz collimator aligner.

30. The method of claim 29 wherein the step of providing a second quartz collimator aligner further comprises the steps of:

providing a second quartz collimator holder having an aperture therein; and

locating the second optical fiber holder and the second lens within the aperture in the second quartz collimator holder.

31. The method of claim 30 wherein the steps of providing the core further comprises the steps of:

providing a core assembly holder located between the first polarizer and the second polarizer; and

disposing the polarization rotation means within the core assembly holder.

32. The method of claim 31 wherein the step of providing the core further comprises:

providing a core holder having at least one aperture disposed therein; and

wherein the method further comprises the step of;

providing a plurality of solder joints connecting the second collimator holder to the core holder,

the step of providing a plurality of solder joints further comprising the step of at least partially disposing each of a portion of the plurality of solder joints in each of the at least one aperture in the core holder.

33. The method of claim 32 wherein the step of providing a plurality of solder joints further comprises the step of making at least a second portion of the solder joints flux-less solder joints.

34. The method of claim 33 wherein the at least a portion of the second collimator holder comprises brass;

and wherein the step of providing flux-less solder joints further comprises the steps of gold plating second collimator holder.

35. The method of claim 34 wherein the gold plating step further comprises the step of gold plating the second collimator holder to a thickness of 90 micrometers.

36. The method of claim 34 wherein the solder is Sn63Pb37.