Patent ID: 11942997
Assignee: INFINERA CORPORATION
Field: Telecommunications (Electrical engineering)
Classification: CPC H | IPC H

Claim 0:
1. A method of tuning a local oscillator laser in a coherent receiver, wherein the laser includes a first grating, a second grating, a phase section, a first heater adjacent the first grating, a second heater adjacent the second grating, and a third heater adjacent the phase section, the method comprising the steps of:
selecting a first range of frequencies;
selecting a first subrange of frequencies in the first range of frequencies;
changing a first power supplied to the third heater to thereby adjust a frequency of the local oscillator laser from a first frequency to a second frequency in a first plurality of successive frequency increments, the first and second frequencies being within the first subrange of frequencies;
changing a second power supplied to the first heater and a third power supplied to the second heater to thereby adjust the frequency of the local oscillator laser from the second frequency to a third frequency;
changing the first power to thereby adjust the frequency of the local oscillator laser from the third frequency to a fourth frequency in a second plurality of successive frequency increments, the third and fourth frequencies being within a second subrange of frequencies that is in the first range of frequencies;
selecting a second range of frequencies;
changing the second power and the third power to thereby adjust the frequency of the local oscillator laser from the fourth frequency to a fifth frequency;
changing the first power to thereby adjust the frequency of the local oscillator laser from the fifth frequency to a sixth frequency in a third plurality of successive frequency increments, the fifth and sixth frequencies being within a third subrange of frequencies that is within the second range of frequencies, wherein the coherent receiver is operable to detect data carried by a received optical signal when the local oscillator laser has the sixth frequency.