Electro-optic transceiver module with wavelength compensation

Patent metadata

Field	Value
Publication number	US-10177841-B2
Application number	US-201615087562-A
Country	US
Kind code	B2
Filing date	Mar 31, 2016
Priority date	Mar 31, 2016
Publication date	Jan 8, 2019
Grant date	Jan 8, 2019

Abstract

An electro-optic transceiver module, method of manufacturing, and method of transmitting signals are provided that allow multiple optical signals at different wavelengths (e.g., according to CWDM) to be combined for transmission via a number of optical fibers that is smaller than the number of electrical channels according to which the optical signals were generated. Thus, CWDM may be used in connection with lower-cost VCSEL technology (e.g., as opposed to higher-cost edge-emitting lasers) by providing for wavelength compensation at the VCSEL driver to offset any changes in wavelength that may have otherwise occurred at the VCSELs. In particular, a microcontroller of the electro-optic transceiver module correlates a monitored temperature of the VCSELs to an actual wavelength of the corresponding optical signals transmitted by the respective VCSELS and determined an adjustment in a current supplied by the VCSEL driver to each VCSEL to achieve more precise and consistent wavelengths at the VCSELs.

First claim

What is claimed is:

1. An electro-optic transceiver module comprising:
a plurality of vertical-cavity surface-emitting lasers (VCSELs), wherein each VCSEL is configured to convert an electrical signal to a corresponding optical signal for transmission through a fiber optic cable;
at least one VCSEL driver comprising driving circuitry and configured to control operation of a corresponding VCSEL of the plurality of VCSELs such that each optical signal has a wavelength that is different from a wavelength of every other optical signal of the plurality of VCSELs;
an optical multiplexer coupled to the plurality of VCSELs, wherein the optical multiplexer is configured to:
receive a plurality of optical signals from the plurality of VCSELs,
combine the plurality of optical signals into a single combined optical signal comprising multiple wavelengths, and
transmit the single combined optical signal through a single optical fiber; and

a microcontroller configured to:
independently monitor a temperature of each VCSEL,
correlate the monitored temperature of each VCSEL to an actual wavelength of the corresponding optical signal transmitted by each respective VCSEL,
based only on the correlation, determine an adjustment in a current supplied by the at least one VCSEL driver to each respective VCSEL for which the actual wavelength of the optical signal transmitted is outside a tolerated band of desired wavelengths, and
communicate the adjustment to the at least one VCSEL driver, wherein the adjustment to the at least one VCSEL driver maintains the single combined optical signal within a tolerated band of desired multiplex wavelengths.

2. The electro-optic transceiver module of claim 1 , wherein the at least one VCSEL driver is configured to control operation of the corresponding VCSEL by selecting a wavelength of the optical signal to be outputted by the corresponding VCSEL according to coarse wavelength division multiplexing (CWDM).

3. The electro-optic transceiver module of claim 1 further comprising a thermoelectric cooler (TEC) configured to remove heat from the plurality of VCSELs, and a TEC driver comprising driving circuitry configured to control operation of the TEC, wherein the microcontroller is configured to selectively activate and deactivate the TEC based on the monitored temperature of at least one of the plurality of VCSELs to maintain a temperature of the at least one of the plurality of VCSELs within a certain range of predefined temperatures.

4. The electro-optic transceiver module of claim 1 further comprising a plurality of TECs, each TEC configured to remove heat from a corresponding VCSEL of the plurality of VCSELs, and at least one TEC driver comprising driving circuitry configured to control operation of one or more corresponding TECs, wherein the microcontroller is configured to selectively activate and deactivate each TEC based on the monitored temperature of the corresponding VCSEL to maintain a temperature of the corresponding VCSEL within a certain range of predefined temperatures.

5. The electro-optic transceiver module of claim 1 , wherein the plurality of VCSELs consists of four VCSELs.

6. The electro-optic transceiver module of claim 1 , wherein the plurality of VCSELs is a first plurality of VCSELs, wherein the electro-optic transceiver module further comprises a second plurality of VCSELs, and wherein each of the first and second pluralities of VCSELs consists of two VCSELs.

7. The electro-optic transceiver module of claim 1 , wherein the at least one VCSEL driver is configured to detect a current of the corresponding VCSEL.

8. The electro-optic transceiver module of claim 7 , wherein the microcontroller is configured to monitor a temperature of each VCSEL by receiving an indication of the current detected by the at least one VCSEL driver and determining a temperature of the corresponding VCSEL based on the respective indication of current.

9. A method of transmitting multiple optical signals at different wavelengths over a single optical fiber, the method comprising:
using a plurality of vertical-cavity surface-emitting lasers (VCSELs) to convert a plurality of electrical signals to corresponding optical signals, wherein each electrical signal is provided to a respective VCSEL via a corresponding VCSEL driver, and wherein each optical signal has a wavelength that is different from a wavelength of every other optical signal of the plurality of VSCELs;
receiving at an optical multiplexer the optical signals from the plurality of VCSELs; combining, via the optical multiplexer, the optical signals into a single combined optical signal comprising multiple wavelengths;
transmitting the single combined optical signal through a single optical fiber;
independently monitoring a temperature of each VCSEL of the plurality of VCSELs;
correlating the monitored temperature of each VCSEL to an actual wavelength of the corresponding optical signal transmitted by each respective VCSEL;
based only on the correlation, determining an adjustment in a current supplied by the VCSEL driver to each respective VCSEL for which the actual wavelength of the optical signal transmitted is outside a tolerated band of desired wavelengths; and
communicating the adjustment to each corresponding VCSEL driver, wherein the adjustment to the at least one VCSEL driver maintains the single combined optical signal within a tolerated band of desired multiplex wavelengths.

10. The method of claim 9 , wherein the wavelength of each optical signal to be outputted by the plurality of VCSELs is selected according to coarse wavelength division multiplexing (CWDM).

11. The method of claim 9 further comprising using at least one thermoelectric cooler (TEC) to remove heat from the plurality of VCSELs so as to maintain a temperature of the plurality of VCSELs within a certain range of predefined temperatures based on the monitored temperature of at least one of the plurality of VCSELs.

12. The method of claim 9 further comprising detecting a current of each VCSEL using the corresponding VCSEL driver.

13. The method of claim 12 , wherein monitoring a temperature of each VCSEL of the plurality of VCSELs comprises receiving an indication of the current detected by the VCSEL
driver and determining a temperature of the corresponding VCSEL based on the respective indication of current.

14. A method of manufacturing an electro-optic transceiver module comprising:
providing a plurality of vertical-cavity surface-emitting lasers (VCSELs), wherein each VCSEL is configured to convert an electrical signal to a corresponding optical signal for transmission through a fiber optic cable;
connecting at least one VCSEL driver to the plurality of VCSELs, wherein the at least one VCSEL driver comprises driving circuitry and is configured to control operation of a corresponding VCSEL of the plurality of VCSELs such that each optical signal has a wavelength that is different from a wavelength of every other optical signal of the plurality of VSCELs;
coupling an optical multiplexer to the plurality of VCSELs, wherein the optical multiplexer is configured to:
receive a plurality of optical signals from the plurality of VCSELs,
combine the plurality of optical signals into a single combined optical signal comprising multiple wavelengths, and
transmit the single combined optical signal through a single optical fiber; and

connecting a microcontroller to the at least one VCSEL driver, wherein the microcontroller is configured to:
independently monitor a temperature of each VCSEL,
correlate the monitored temperature of each VCSEL to an actual wavelength of the corres

Assignees

• Mellanox Technologies Ltd

Inventors

• Mentovich Elad
• Kalifa Itshak
• Rockman Sylvie
• Webman Alon
• Kimhi Dalit
• Dikopoltsev Alex

Classifications

• H04B10/503

  Laser transmitters · CPC title

• H04J14/02

  Wavelength-division multiplex systems · CPC title

• H04B10/0795 Primary

  Performance monitoring; Measurement of transmission parameters · CPC title

• H04B10/2504

  Electricity · mapped topic

• H04B10/572

  Wavelength control · CPC title