Claims
- 1. A method of supporting communication comprising:
coupling first and second differential transistor pairs to a laser diode at a common node; setting a current source to provide a first current; switching the first current through the diode or an alternate path to selectively bias the diode or shunt the first current; and modulating a light energy output transmitted from the diode by selectively switching a second current through the diode while the first current is switched to bias the diode, wherein the light energy output of the diode is proportional to a total current through the diode; wherein switching includes switching the first current on or off in less than a single bit time.
- 2. A method as in claim 1 further comprising coupling the light energy output of the diode to a fiber and transmitting information over an optical network via time division multiplexing.
- 3. A method as in claim 1 further comprising disposing a resistor in series with the diode, through which the first and second current flow when the diode is in a biased mode.
- 4. A method as in claim 1 further comprising coupling the light energy output of the diode to a fiber of a passive optical network.
- 5. A method as in claim 1 further comprising in between transmitting data packets, adjusting the first or second current.
- 6. A method as in claim 1, wherein an output of the first differential driver is switched to either of two states to selectively bias the diode and the second differential driver is switched between either of two states to modulate the diode.
- 7. A burst mode laser driver system comprising:
a modulation differential transistor pair coupled to a laser diode, the modulation differential transistor pair controlling a modulation current through the laser diode; a bias differential transistor pair coupled to the laser diode, the bias differential transistor pair controlling a bias current through the laser diode and switching the bias current on or off in less than a single bit time of modulated data in a burst mode; wherein the modulation differential transistor pair and the bias differential transistor pair are coupled to the laser diode at a common node.
- 8. A method for switching a diode comprising:
coupling first and second differential transistor pairs to a laser diode at a common node; producing a first differential output comprising complementary first and second switch control signals coupled to the first differential transistor pair; setting the first differential output to either of two states to selectively bias the diode on or off in less than a single bit time; producing a second differential output comprising complementary third and fourth switch control signals coupled to the second differential transistor pair; and setting the second differential output to either of two states to selectively modulate the diode for transmitting binary information.
- 9. A method as in claim 8, wherein the first and second control signals drive switches of the first differential transistor pair that are used to selectively switch a bias current through the diode or an alternate path.
- 10. A method as in claim 8, wherein the third and fourth control signals drive switches of the second differential transistor pair that are used to selectively switch a modulation current through the diode or an alternate path.
- 11. A high speed switching driver comprising:
first and second differential transistor pairs coupled to a laser diode at a common node; a first circuit device that produces a first differential output comprising complementary first and second signals coupled to the first differential transistor pair, the first differential output being set to either of two states; a second circuit device that produces a second differential output comprising complementary third and fourth signals coupled to the second differential transistor pair, the second differential output being set to either of two states; wherein the diode is selectively biased on or off in less than a single bit time depending on the first differential output of the first circuit device and is selectively modulated depending on the second differential output of the second circuit device.
- 12. A high speed switching driver as in claim 11, wherein the first and second control signals drive switches that are used to selectively switch a bias current through the diode or an alternate path.
- 13. A high speed switching driver as in claim 11, wherein the third and fourth control signals drive switches that are used to selectively switch a modulation current through the diode or an alternate path.
- 14. Apparatus for high speed switching comprising:
means for coupling first and second differential transistor pairs to a laser diode at a common node; means for setting a current source to provide a first current; means for switching the first current through the diode or an alternate path to selectively bias the diode or shunt the first current, the first current switched on or off in less than a single bit time; and means for modulating a light energy output transmitted from the diode by selectively switching a second current through the diode while the first current is switched to bias the diode, wherein the light energy output of the diode is proportional to a total current through the diode.
RELATED APPLICATION
[0001] This application is a continuation of U.S. application Ser. No. 09/975,082, filed Oct. 11, 2001. The entire teachings of the above application are incorporated herein by reference.
Continuations (1)
|
Number |
Date |
Country |
Parent |
09975082 |
Oct 2001 |
US |
Child |
10704348 |
Nov 2003 |
US |