Study on spectral parameter difference of output light of lithium niobate integrated optical modulator

Lithium niobate integrated optical modulator is the core component of interferometric fiber optic gyroscope, and its performance has an important influence on the performance indicators of fiber optic gyroscope. The output light of lithium niobate integrated optical modulator are generally considered to have the same central wavelength and spectral width. In this paper, it is proved that there is a non-negligible difference in the central wavelength between the outgoing light through several groups of experiments. The temperature characteristics of spectral parameters are discussed, in which the wavelength difference changes obviously with temperature. In the temperature range of [−40,60] °C, the wavelength difference first increases, reaches the maximum at about 50 °C, and then decreases with the increase of temperature. The spectral width difference does not change significantly with temperature.