Method And Apparatus For Optical Transmission In A Communication Network

• US 20140341593A1
• Filed: 05/16/2014
• Published: 11/20/2014
• Est. Priority Date: 05/16/2013
• Status: Abandoned Application

• Current Assignee: Alcatel-Lucent USA, Inc. (Nokia Corporation)
• Original Assignee: Alcatel-Lucent SA (Nokia Corporation), Alcatel-Lucent USA, Inc. (Nokia Corporation)
• Inventors: Vetter, Peter, van Veen, Doutje T., Farah, Robert, Poehlmann, Wolfgang
• Application Number:
  US14/279,642
• Publication Number:
  US 20140341593A1
• Time in Patent Office: Days
• US Class Current: 398/201
• CPC Class Codes: H04B 10/272 Star-type networks or tree-type networks
• CPC Class Codes: H04B 10/504 using direct modulation

Abstract

A manner of mitigating the self heating effect of a laser or other light source such as a laser in a network node of a communication network. A self-heating mitigation module is provided, the self-heating mitigation module includes one or both of a self-heating adjustment module to accelerate self heating at the beginning of a transmission and a sub-threshold lasing module that applies a sub-threshold current between transmissions. The self-heating adjustment module and the sub-threshold lasing module are preferable both used together and driven by a common signal, for example the burst_enable signal that facilitates transmission from the light source.

Claims

1. A network node, comprising

a laser light source;

and

circuitry for driving the laser light source, wherein the circuitry comprises a self-heating mitigation module.

2. The network node of claim 1, further comprising:

a processor for controlling operation of components of the network node; and

a memory device for storing executable program instructions.

3. The network node of claim 2, further comprising executable program instructions stored on the memory device that when executed cause the network node to form a transmission preamble initially dominated by 1 bits.

4. The network node of claim 3, wherein the formed preamble gradually assumes a bit pattern comprising alternating 1 bits and 0 bits.

5. The network node of claim 1, wherein the self-heating mitigation module comprises a sub-threshold lasing module configured to selectively apply a sub-threshold a sub-threshold current to the laser light source.

6. The network node of claim 5, wherein the sub-threshold lasing module is controlled by a burst_enable signal generated in the network node.

7. The network node of claim 1, wherein the self-heating mitigation module comprises a self-heating adjustment module configure to accelerate the self-heating of the laser light source.

8. The network node of claim 7, wherein the self-heating adjustment module comprises an RC circuit configured for producing an overshoot of laser bias current at the beginning of a transmission.

9. The network node of claim 6, wherein the self-heating adjustment module is controlled by a burst_enable signal generated in the network node.

10. A method operating a network node comprising a laser light source, the method comprising accelerating self heating of the laser light source at the beginning of a transmission.

11. The method of claim 10, wherein accelerating self heating of the laser light source comprises forming a transmission preamble initially dominated by 1 bits.

12. The method of claim 10, wherein accelerating self heating of the laser light source comprises applying an overshoot of the laser current at the beginning of a transmission.

13. The method of claim 12, wherein the applying an overshoot of the laser current is controlled by a burst_enable signal.

14. The method of claim 10, further comprises selectively applying a sub-threshold lasing current to the laser light source.

15. The method of claim 14, wherein the sub-threshold lasing current is only applied when the laser light source is in a non-transmitting state.

16. The method of claim 14, wherein the sub-threshold lasing current application is controlled by a burst_enable signal.

17. The method of claim 14, further comprising deactivating application of the sub-threshold lasing current when the laser light source is not operated for extended periods.