Erbium (Er) doped Lithium Niobate (LiNbO3) is a type of crystal that has potential applications in the field of optics and photonics. Erbium ions, when doped into the lithium niobate crystal, exhibit strong absorption and emission properties in the near-infrared region. This makes Er:LiNbO3 a suitable material for use in fiber amplifiers and other optical communication systems. Additionally, the large nonlinear susceptibility of lithium niobate allows for the efficient frequency conversion and modulation of light, making Er:LiNbO3 a useful material for nonlinear optical applications such as frequency mixing, optical parametric amplification, and optical parametric oscillation.