Power ratio measurement of dual wavelength dye laser with picometer-level wavelength difference

Dual wavelength lasers have wide applications in optical communication equipment, lidar, and other fields. The measurement and control of dual wavelength laser power ratio affect the application value of dual wavelength lasers in these fields directly. The dual wavelength dye laser used in the experiment has a wavelength difference of only several picometers. Based on this demand, our paper innovatively proposes a measurement method that using a scanning FP interferometer to characterize the power ratio. The linear correlation between spectral response and incident light power was verified through the establishment of theoretical models and experimental verification. On this basis, the optimization of optical layout design and the design of automatic recognition software can be carried out separately to achieve online monitoring of power ratio. Finally, the device was used for long-term experimental assessment, and the results showed that the comprehensive error of dual wavelength power ratio measurement based on scanning FP interferometer was less than ± 3%, which met the experimental requirements.