Interconnect structure for coupling an electronic unit and an optical unit, and optoelectronic module
An optoelectronic module is provide and includes an electronic unit, an optical unit, and an interconnect structure. The electronic unit is capable of outputting and/or receiving electric signals, while the optical unit is capable of converting the electric signals into optical signals. The interconnect structure connects the electronic unit and the optical unit, and includes an electrically conducting substrate and a pair of transmission leads connecting electronic unit and the optical unit. The pair of transmission leads includes a signal lead and a ground lead having lower impedance than the signal lead.
1. An optoelectronic module, comprising:
a driver circuit configured to output and/or receive an electrical signal;
a laser configured to convert the electrical signal into an optical signal;
an interconnect structure connecting the driver circuit and the laser, the interconnect structure comprising an electrically conductive substrate and a pair of transmission leads connecting the driver circuit and the laser and having a signal lead and a ground lead having lower impedance than the signal lead; and
a ground plane layer underlying the ground lead, wherein the ground lead is electrically coupled to the ground plane layer;
wherein an impedance of the signal lead is defined by its width and a distance to the ground plane layer, and the ground lead has a width that is larger than a width of the signal lead.
2. The optoelectronic module of claim 1 , wherein the ground lead has a width that is at least five times larger than the width of the signal lead.
3. The optoelectronic module of claim 1 , wherein the ground lead is electrically coupled to the ground plane layer by a via.
4. The optoelectronic module of claim 1 , wherein the signal lead is connected to an anode of the laser.
5. The optoelectronic module of claim 1 , wherein the ground lead is connected to a cathode of the laser.
6. The optoelectronic module of claim 1 , further comprising an array of lasers including the laser.
7. The optoelectronic module of claim 6 , further comprising a 12-channel laser mounted in the electrically conductive substrate.
8. The optoelectronic module of claim 1 , further comprising an optical receiver and an amplifying circuit for amplifying output signals of the optical receiver.
9. The optoelectronic module of claim 8 , wherein the optical receiver includes an array of PIN (positive intrinsic negative) photo diodes and the amplifying circuit includes a transimpedance amplifier (TIA) array.
10. The optoelectronic module of claim 1 , wherein the laser is a vertical cavity surface emitting laser (VCSEL).
11. The optoelectronic module of claim 1 , wherein a majority of a return signal is guided by the ground lead rather than the signal lead.
12. An optoelectronic module, comprising:
a driver array configured to output and/or receive electrical signals;
a laser array configured to convert the electrical signals into optical signals;
an interconnect structure connecting the driver array and the laser array, the interconnect structure comprising an electrically conductive substrate and transmission leads connecting the driver array and the laser array and having signal leads and ground leads having lower impedance than the signal leads; and
a ground plane layer underlying the ground leads, wherein the ground leads are electrically coupled to the ground plane layer;
wherein the ground leads have a width that is larger than a width of the signal leads.
13. The optoelectronic module of claim 12 , wherein the ground leads have a width that is at least five times larger than the width of the signal leads.
14. The optoelectronic module of claim 12 , wherein the ground leads are electrically coupled to the ground plane layer by vias.
15. The optoelectronic module of claim 12 , wherein each of the signal leads are connected to an anode of a laser of the laser array.
16. The optoelectronic module of claim 12 , wherein each of the ground leads are connected to a cathode of a laser of the laser array.
17. The optoelectronic module of claim 12 , the laser array comprising vertical cavity surface emitting laser (VCSEL).
18. The optoelectronic module of claim 12 , wherein the signal leads are narrower than the ground leads.
19. The optoelectronic module of claim 12 , wherein a majority of return signals are guided by the ground leads rather than adjacent signal leads.
20. An optoelectronic module, comprising:
a driver array configured to output and/or receive electrical signals;
a laser array configured to convert the electrical signals into optical signals;
an interconnect structure connecting the driver array and the laser array, the interconnect structure comprising an electrically conductive substrate and transmission leads connecting the driver array and the laser array and having signal leads and ground leads having lower impedance than the signal leads; and
a ground plane layer underlying the ground leads, wherein the ground leads are electrically coupled to the ground plane layer;
wherein the ground leads are electrically coupled to the ground plane layer by vias and the signal leads are narrower than the ground leads such that return signals are guided by the ground leads.