Influence of the Parameters of a Heater Array Inducing a Thermooptic Long-Period Grating on Its Power Consumption

We investigate experimentally and theoretically the power consumption of a notch filter using a thermooptic long-period grating, which is induced by a heater array consisting of periodic heaters and pads made of metal thin-film. Since the power consumed by the heater array is converted to joule heat that generates the thermooptic long-period grating, the characteristics of the notch filter are dynamically controlled by adjusting it. The power necessary for appropriate coupling efficiency depends on the parameters of the heater array, which are the width and length of a heater, pad width, and the thickness of the thin-film. To analyze the dependence, we fabricated several notch filters with different heater lengths and pad widths. In addition, we simulated the influence of the parameters on the power consumption using some approximation and assumptions. Through the experiment and the simulation, it is shown that the experimentally obtained changes of the consumed power depending on the parameters follow a trend achieved theoretically. Moreover, the experimental results show that the consumed power decreases by more than 50% as the heater length is reduced from 500 to 50 mum. Finally, we suggest a few guidelines on the parameters required to reduce the power consumption.