Analysis of tuning in a photonic crystal multichannel filter containing coupled defects

We investigate the tuning properties in a photonic crystal multichannel filter made of coupled defects. The tuning in defect modes is achieved by the temperature change as well as the applied bias voltage. The temperature tuning arises from the thermal expansion and thermal-optical effects in the constituent layers. It is found that the resonant peaks are red-shifted as the temperature increases. In the voltage tuning, the defect modes are blue-shifted as the positive bias is applied, whereas they are red-shifted when the bias voltage is negative. The position of peak wavelength is further shown to linearly decrease with the applied voltage. The analysis of tunable features reveals that such a multichannel filter can be used not only a tunable device but a temperature- or voltage sensor. (C) 2012 Elsevier GmbH. All rights reserved.