An apparatus (10) and method for dynamic frequency control of a photonic band gap crystal includes an acoustic band gap crystal (12) having a defect site (14), a photonic band gap crystal (20) in the defect site of the acoustic band gap crystal (12), and a sound wave generator (40) coupled to the acoustic band gap crystal (12). Consequently, acoustic waves in the acoustic band gap crystal (12) can be used to controllably alter transmission properties of the photonic band gap crystal (20) and thereby modulate the transmission of electromagnetic radiation through the photonic band gap crystal (20). Acoustic waves in the acoustic band gap crystal (12) can squeeze the photonic band gap crystal (20) to change its properties, including one or more of lattice constant, symmetry, and optical refractive index contrast.