Method of differentially connecting photonic devices

• US 6,952,297 B2
• Filed: 09/20/2001
• Issued: 10/04/2005
• Est. Priority Date: 09/21/2000
• Status: Active Grant

• Current Assignee: Sumitomo Electric Device Innovations, U.S.A., Inc. (Sumitomo Corporation)
• Original Assignee: Emcore Corporation
• Inventors: Mansur, Dan, Wickman, Randy
• Primary Examiner(s): Ben, Loha
• Application Number:
  US09/957,257
• Publication Number:
  US 20020033985A1
• Time in Patent Office: 1,475 Days
• Field of Search: 359/245, 359/248, 345/87, 345/89, 345/95, 345/211, 363/54, 327/360, 327/438, 327/514, 398/140, 398/182, 708/844
• US Class Current: 359/245
• CPC Class Codes: G02F 1/0121 Operation of devices; Circuit arrangements, not otherwise provided for in this subclass
• CPC Class Codes: H04B 10/504 using direct modulation

Abstract

A method and apparatus are provided for driving an electro-optic converter assembly with an information signal. The method includes the steps of disposing a resistor having a resistance substantially equal to a resistance of the electro-optic converter adjacent the electro-optic converter, coupling the electro-optic converter and resistor together, in series, to form a current loop, driving the electro-optical converter end of the current loop with the information signal and driving the resistor end of the current loop with an opposite polarity of the information signal.

Claims

1. A method of driving an electro-optic converter assembly with an information signal, such method comprising the steps of:

disposing a resistor having a resistance substantially equal to a resistance of the electro-optic converter adjacent the electro-optic converter;

coupling the electro-optic converter and resistor together, in series, to form a current loop;

driving the electro-optic converter end of the current loop with the information signal; and

driving the resistor end of the current loop with an opposite polarity of the information signal.

2. The method of driving an electro-optic converter assembly as in claim 1 wherein the step of disposing the resistor adjacent the electro-optic converter further comprises fabricating the electro-optic converter and resistor on a common substrate.

3. The method of driving an electro-optic converter assembly as in claim 2 further comprising fabricating the resistor and electro-optic converter on the common substrate as substantially identical structures.

4. The method of driving an electro-optic converter assembly as in claim 3 wherein the step of coupling the electro-optic converter and resistor together to form a current loop further comprises coupling a substrate end of the electro-optic converter and resistor to the substrate.

5. The method of driving an electro-optic converter assembly as in claim 4 further comprising coupling the substrate end to a ground potential.

6. The method of driving an electro-optic converter assembly as in claim 2 further comprising etching a well between the electro-optical converter and resistor.

7. The method of driving an electro-optic converter assembly as in claim 1 further comprising disposing a conductive trace across a top layer of the resistor interconnecting the top layer and an intrinsic layer of the resistor.

8. The method of driving an electro-optic converter assembly as in claim 1 further comprising forming connections with the electro-optic converter and resistor on a common side of the substrate.

9. The method of driving an electro-optic converter assembly as in claim 8 wherein the step of coupling the electro-optic converter and resistor to a differential amplifier further comprises coupling the electro-optic converter to a positive output of the differential amplifier and the resistor to a negative polarity output of the differential amplifier.

10. The method of driving an electro-optic converter assembly as in claim 1 further comprising coupling the electro-optic converter and resistor to a differential amplifier.

11. An apparatus for driving an electro-optic converter assembly with an information signal, such apparatus comprising:

a resistor having a resistance substantially equal to a resistance of the electro-optic converter disposed adjacent the electro-optic converter;

means for coupling the electro-optic converter and resistor together, in series, to form a current loop;

means for driving the electro-optical converter end of the current loop with the information signal; and

means for driving the resistor end of the current loop with an opposite polarity of the information signal.

12. The apparatus for driving an electro-optic converter assembly as in claim 11 further comprising the electro-optic converter and resistor disposed on a common substrate.

13. The apparatus for driving an electro-optic converter assembly as in claim 12 further comprising the resistor and electro-optic converter fabricated on the common substrate as substantially identical structures.

14. The apparatus for driving an electro-optic converter assembly as in claim 13 wherein the means for coupling the electro-optic converter and resistor together to form a current loop further comprises means for coupling a substrate end of the electro-optic converter and resistor to the substrate.

15. The apparatus for driving an electro-optic converter assembly as in claim 14 further comprising means for coupling the substrate and to a ground potential.

16. The apparatus for driving an electro-optic converter assembly as in claim 12 further comprising a well etched between the electro-optic component and resistor.

17. The apparatus for driving an electro-optic converter assembly as in claim 11 further comprising a conductive trace disposed across a top layer of the resistor interconnecting the top layer and an intrinsic layer of the resistor.

18. The apparatus for driving an electro-optic converter assembly as in claim 11 further comprising means for forming connections with the electro-optic converter and resistor on a common side of the substrate.

19. The apparatus for driving an electro-optic converter assembly as in claim 18 wherein the means for coupling the electro-optic converter and resistor to a differential amplifier further comprises means for coupling the electro-optic converter to a positive output of the differential amplifier and the resistor to a negative polarity output of the differential amplifier.

20. The apparatus for driving an electro-optic converter assembly as in claim 11 further comprising means for coupling the electro-optic converter and resistor to a differential amplifier.

21. An apparatus for driving an electro-optic converter assembly with an information signal, such apparatus comprising:

the electro-optic converter;

a resistor having a resistance substantially equal to a resistance of the electro-optic converter disposed adjacent the electro-optic converter and operably coupled in series with the electro-optic converter to form a current loop; and

an amplifier adapted to drive the electro-optic converter end of the current loop with the information signal and the resistor end of the current loop with an opposite polarity of the information signal.

22. The apparatus for driving an electro-optic converter assembly as in claim 21 further comprising the electro-optic converter and resistor disposed on a common substrate.

23. The apparatus for driving an electro-optic converter assembly as in claim 22 further comprising the resistor and electro-optic converter fabricated on the common substrate as substantially identical structures.

24. The apparatus for driving an electro-optic converter assembly as in claim 23 wherein the current loop further comprises a connection between the electro-optic converter and resistor and the substrate.

25. The apparatus for driving an electro-optic converter assembly as in claim 24 further comprising a connection between the substrate and ground potential.

26. The apparatus for driving an electro-optic converter assembly as in claim 22 further comprising a well etched between the electro-optic converter and resistor.

27. The apparatus for driving an electro-optic converter assembly as in claim 21 further comprising a conductive trace disposed across a top layer of the resistor interconnecting the top layer and an intrinsic layer of the resistor.

28. The apparatus for driving an electro-optic converter assembly as in claim 21 further comprising a set of respective connections with the electro-optic converter and resistor disposed on a common side of the substrate.

29. The apparatus for driving an electro-optic converter assembly as in claim 28 wherein the coupling between the current loop and the differential amplifier further comprises a first conductor for coupling the electro-optic converter to a positive output of the differential amplifier and a second conductor for coupling the resistor to a negative polarity output of the differential amplifier.

30. The apparatus for driving an electro-optic converter assembly as in claim 21 further comprising a connection between the electro-optic converter and resistor and the differential amplifier.

31. An optical transmitter assembly comprising:

a substrate coupled to a ground potential;

an electro-optic converter disposed on the substrate with a ground connection of the electro-optic converter coupled to the substrate;

a resistor having a resistance value substantially equal to a resistance of the electro-optic converter disposed on the substrate adjacent the electro-optic converter with a ground end of the resistor coupled to the substrate; and

a differential amplifier with a first driving output of the differential amplifier operably coupled to an input of the electro-optic converter and a second driving output of the differential amplifier coupled to an input of the resistor.

32. A method of driving an electro-optic converter, such method comprising the steps of:

disposing the electro-optic converter on a grounded substrate;

disposing a resistor having a resistance substantially equal to a resistance of the electro-optic converter on the grounded substrate adjacent the electro-optic converter; and

differentially driving the resistor and electro-optic converter in parallel from opposite polarity outputs of a differential amplifier.

33. A method of driving an electro-optic converter through a differential amplifier, such method comprising the steps of:

disposing the electro-optic converter on a grounded substrate;

disposing a resistor having a resistance substantially equal to a resistance of the electro-optic converter on the grounded substrate adjacent the electro-optic converter; and

coupling a first polarity output of the differential amplifier to the electro-optic converter and an opposite polarity output of the differential amplifier to the resistor.

34. A method of providing an electro-optic converter assembly for transmitting an information signal, such method comprising the steps of:

disposing the electro-optic converter on a grounded substrate; and

disposing a resistor having a resistance substantially equal to a resistance of the electro-optic converter on the grounded substrate adjacent the electro-optic converter, said electro-optic converter being adapted to receive the information signal and said resistor being adapted to receive an opposite polarity of the information signal.

35. A method of driving an electro-optic converter through a differential amplifier, such method comprising the steps of:

disposing a first and second electro-optic converters having substantially equal resistance on a ground plane; and

coupling a first polarity output of the differential amplifier to the first electro-optic converter and an opposite polarity output of the differential amplifier to the second electro-optic converter.