Experimental investigation of tunable defect modes in the comb-like photonic crystals

In this paper, a tunable defect mode has been demonstrated. A variable capacitance diode has been introduced into a 1D comb-like photonic crystal and a defect mode occurs in the photonic band gap. Frequency of the defect mode is controlled by the reverse bias voltage applied to the diode. As the reverse bias voltage applied to the diode increases, the defect peak in the transmission spectrum shifts towards high frequency. The transmission spectrum also has been obtained by simulation and the results agree with the experimental results.