Fe:LiNbO3 is a type of crystal material that is doped with Iron ions. It is known for its unique electro-optic and magneto-optic properties and has a wide range of applications in photonics, including in modulators, switches, and other optical communication devices. Fe:LiNbO3 is also used as a substrate material in the fabrication of micro-electromechanical systems (MEMS) due to its high stability and low loss. Additionally, its piezoelectric and ferroelectric properties make it suitable for use in ultrasonic transducers, sensors, and other applications in the field of acoustics.