Patent ID: 9369210
Filing Date: 2016-06-14
CPC Classification: G02F,H04B

Claim Text:
1. A system to calibrate optical modulators, the system comprising: an optical modulator configured to output a modulated optical signal based on a first electrical signal, an optical power of and a polarity of data carried by the modulated optical signal being dependent on a temperature of the optical modulator; an optical signal detection circuit optically coupled to the optical modulator and configured to generate a second electrical signal based on the optical power of the modulated optical signal; a thermal tuning circuit coupled to the optical signal detection circuit and configured to adjust the temperature of the optical modulator in response to a power of the second electrical signal being less than a particular power threshold; a data polarity detection circuit configured to compare the polarity of the data carried by the modulated optical signal with a polarity of data carried by the first electrical signal; a data polarity switching circuit configured to switch the polarity of data carried by a third electrical signal in the system in response to the polarity of the data carried by the modulated optical signal being opposite from the polarity of the data carried by the first electrical signal; and a signal generator circuit configured to adjust a data pattern of the data of the first electrical signal, the signal generator circuit configured to generate a first data pattern with an approximately fifty percent duty-cycle that oscillates between a high level and a low level and to generate a second data pattern that randomly oscillates between the high level and the low level, wherein the data polarity detection circuit is configured to detect the polarity of the data carried by the modulated optical signal when the data of the first electrical signal follows the first data pattern and the thermal tuning circuit is configured to adjust the temperature of the optical modulator when the data of the first electrical signal follows the second data pattern.