Optical transceiver calibration system and method
View Patent ↗An optical transceiver calibration system and manufacturing method to fabricate a dual closed loop control transceiver are provided. The calibration system and method includes measuring an operating temperature and determining operational parameters based upon the operating temperature. The operational parameters may include, for example, a target power for transmitting a digital one, a target power for transmitting a digital zero, a modulation current, and a bias current. A bias may be added to the temperature to account for the difference between the temperature at the temperature sensor and the optical equipment. The operational parameters are preferably calculated independently of each other and are used as initial values during operating modes and allow the control loop to converge more quickly. The optics data is may be scanned electronically via bar code or some other electronic format prior to test. The software residing on the module then calibrates and configures the transceiver.
1. A method of configuring an optical transceiver, the method comprising:
calculating a first target current for transmitting a digital one;
calculating a second target current for transmitting a digital zero;
calculating a modulation current;
calculating a bias current, wherein each of the calculating the first target current for transmitting a digital one, the calculating the second target current for transmitting a digital zero, the calculating a modulation current, and the calculating the bias current are based at least in part on a temperature, and wherein the calculating the first target current and the calculating the second target current are independent of each other, wherein the calculating the modulation current and the calculating the bias current is performed at least in part by subtracting a bias from the temperature; and
providing the first target current for transmitting a digital one, the second target current for transmitting a digital zero, the modulation current, and the bias current to the optical transceiver as initial values for transmitting data.
2. The method of claim 1 , wherein the bias represents an approximation of a difference between a temperature sensor and a laser.
3. The method of claim 1 , wherein the modulation current and the bias current are calculated during installation of the optical transceiver.
4. The method of claim 1 , further comprising reading constant values from a bar code, the constant values being used in the calculating of one or more of the first target current, the second target current, the modulation current, and the bias current.
5. The method of claim 4 , wherein the constant values include one or more of a threshold current, an operating current, and a monitor photodiode current at a predetermined temperature.
6. The method of claim 1 , further comprising calculating a voltage bias of a photodiode based at least in part on the temperature.
7. A computer program product embedded in a computer readable storage medium and executable by a processor for calibrating an optical transceiver comprising:
computer program code for retrieving a monitor photodiode current for a predetermined temperature, the monitor photodiode current for the predetermined temperature being a constant for a particular laser device;
computer program code for determining a first target current for transmitting a digital one based at least in part on a current temperature of an optics system and the monitor photodiode current;
computer program code for determining a second target current for transmitting a digital zero based at least in part on the current temperature of the optics system and the monitor photodiode current, the second target current being determined independently of the first target current;
computer program code for determining a modulation current based at least in part on the current temperature of the optics system;
computer program code for determining a bias current based at least in part on the current temperature of the optics system; and
computer program code for providing the first target current, the second target current, the modulation current, and the bias current to the optical transceiver.
8. The computer program product of claim 7 , wherein the computer program code for determining the modulation current includes computer program code for subtracting a bias from the current temperature, the bias representing an approximation of a difference between a temperature sensor and a laser.
9. The computer program product of claim 7 , further comprising computer program code for reading constant values from a bar code, the constant values being used in the determining of one or more of the first target current, the second target current, the modulation current, and the bias current.
10. The computer program product of claim 9 , wherein the constant values include one or more of a threshold current, an operating current, and the monitor photodiode current at the predetermined temperature.
11. The computer program product of claim 7 , further comprising computer program code to cause the computer program code for determining the first target current, the second target current, the modulation current, and the bias current periodically.
12. The computer program product of claim 7 , further comprising computer program code for determining a photo diode voltage bias based at least in part on the current temperature.
13. A laser device driver comprising:
a laser diode;
a temperature sensor positioned to detect a temperature;
a monitor photodiode positioned to detect light emitted from the laser diode;
a laser diode driver communicatively coupled to the laser diode to control the operation of the laser diode; and
a calibration controller communicatively coupled to the laser diode driver and the temperature sensor, the calibration controller configured to calculate a target current for transmitting a digital one, a target current for transmitting a digital zero, a bias current, and a modulation current based at least in part on the temperature, the target current for transmitting a digital zero and the target current for transmitting a digital one being calculated independently of each other and being based at least in part on a monitor photodiode current at a predetermined temperature, the monitor photodiode current being a factory setting.
14. The laser device driver of claim 13 , wherein the temperature sensor detects the temperature of the laser diode driver.
15. The laser device driver of claim 13 , wherein the calibration controller calculates the bias current and the modulation current by at least in part subtracting a bias temperature to account for a difference in temperature between the temperature sensor and laser diode.
16. The laser device driver of claim 13 , further comprising a bar code, the bar code including one or more of a threshold current, an operating current, and a monitor photodiode current at a predetermined temperature.
17. The laser device driver of claim 16 , wherein the calibration controller is further configured to perform one or more calculations using values obtained from the bar code.
18. The laser device driver of claim 13 , wherein the calibration controller is configured to calculate the modulation current and the bias current prior to transmitting data.