Tuning the flow of light in semiconductor-based photonic crystals by magnetic fields

► Semiconductors supply basis for fully tunable photonic crystals and their applications. ► Magnetic-field induces huge dielectric-function variations. ► Plasma reflection and cyclotron resonance control photonic-crystal transparency/opacity. ► Indium Antimonide and Silicon proved as prototype semiconductors. ► Microwave experiments on Indium Antimonide confirm full tunability.