A photonic crystal microcavity with the tunable Q factor has been implemented on the basis of a bound state in the continuum using the advanced liquid crystal cell technology platform. It has been shown that the Q factor of the microcavity changes from 100 to 360 in the voltage range of 0.6 V.

It is shown that in the chloroplast periodic structure with a defect, the resonant absorption of light can be implemented. It is found that the resonant light absorption depends significantly on the position of a defect. In terms of the absorption of light energy, an asymmetric resonator is more efficient than a symmetric one.