Device and a method for controlling a thermo-optical phase shifter

A method for controlling a thermo-optical phase shifter (TOPS) for affecting an optical waveguide based on temperature of the TOPS, said method comprising:

• generating a modulation signal for controlling a driving circuit providing power to the TOPS, wherein generating the modulation signal comprises determining an initial portion of the modulation signal for bringing a temperature of the TOPS from a first level corresponding to a first effective power of the driving circuit to a second level corresponding to a second effective power of the driving circuit, wherein, in case the second effective power is larger than the first effective power, the initial portion of the modulation signal is based on a non-linear function of the first effective power, the second effective power, and a maximum power of the driving circuit, and in case the second effective power is smaller than the first effective power, the initial portion of the modulation signal is based on a non-linear function of the first effective power, the second effective power, and the minimum power of the driving circuit;
• providing the modulation signal to the driving circuit;
• and
• outputting power from the driving circuit to the TOPS, wherein outputting of power comprises toggling between an on state of the driving circuit for outputting a maximum power and an off state of the driving circuit for outputting a minimum power, wherein the modulation signal controls the toggling scheme of the driving circuit for bringing the temperature of the TOPS to the second level and for maintaining the temperature of the TOPS at the second level based on the second effective power output by the driving circuit corresponding to the second level of temperature of the TOPS.