Method for calibrating an optoelectronic device using apd bit error rate
Methods and processes are disclosed for calibrating optoelectronic devices, such as optoelectronic transceivers and optoelectronic receivers, based upon a measured avalanche photodiode bit error rate. In general, the method involves measuring a bit error rate for the avalanche photodiode and adjusting the reverse bias voltage of the avalanche photodiode until the bit error rate is minimized. This process is repeated for each of a variety of different thermal conditions. Information concerning each thermal condition and the corresponding reverse bias voltage is stored in a memory of the optoelectronic device.
1 . A method for calibrating an optoelectronic assembly that includes an avalanche photodiode (APD), the method comprising:
measuring, at a first temperature of the optoelectronic assembly, a bit error rate (BER) associated with the APD;
adjusting an APD bias voltage until the measured BER is minimized for the first temperature;
associating a control value with the APD bias voltage that corresponds to the minimum BER; and
storing, in association with each other, the APD bias voltage control value and the first temperature.
2 . The method as recited in claim 1 , wherein the APD bias voltage control value and the first temperature are stored in a temperature lookup table.
3 . The method as recited in claim 1 , wherein the process of adjusting an APD bias voltage until the measured BER is minimized for the first temperature is performed at least in part by the optoelectronic assembly.
4 . The method as recited in claim 1 , wherein the APD bias voltage control value and the first temperature are stored in the optoelectronic assembly.
5 . The method as recited in claim 1 , wherein the APD bias voltage control value and the first temperature are both digital values.
6 . The method as recited in claim 1 , wherein the first temperature is determined by the optoelectronic assembly.
7 . The method as recited in claim 1 , further comprising generating the APD bias voltage control value.
8 . The method as recited in claim 1 , further comprising performing one of the following until the optoelectronic assembly reaches the first temperature: heating the optoelectronic assembly; or, cooling the optoelectronic assembly.
9 . The method as recited in claim 1 , further comprising:
changing a temperature of the optoelectronic assembly from the first temperature to a second temperature; and
performing the measuring, adjusting, associating and storing processes for the second temperature.
10 . The method as recited in claim 9 , wherein changing the optoelectronic assembly from the first temperature to the second temperature comprises performing one of the following: heating the optoelectronic assembly until the optoelectronic assembly reaches the second temperature; or, cooling the optoelectronic assembly until the optoelectronic assembly reaches the second temperature.
11 . The method as recited in claim 9 , further comprising interpolating between the APD bias voltage control value corresponding to the first temperature and the APD bias voltage control value corresponding to the second temperature to determine an APD bias voltage control value for a third temperature.
12 . The method as recited in claim 11 , further comprising storing, in association with each other, a third temperature and the APD bias voltage control value that corresponds to the third temperature.
13 . The method as recited in claim 9 , further comprising extrapolating from the APD bias voltage control value corresponding to the first temperature and the APD bias voltage control value corresponding to the second temperature, to determine an APD bias voltage control value for a third temperature.
14 . The method as recited in claim 13 , further comprising storing, in association with each other, a third temperature and the APD bias voltage control value that corresponds to the third temperature.