Design And Fabrication Of Rocking Filter For Bi-orthogonal Light Source

The light source is the key component of optical communication and optical sensing.Common broadband light sources include LED light sources,SLD light sources,ASE light sources,etc.However,these broadband light sources do not have polarization characteristics.Researchers need to connect a polarizer behind the light source to obtain polarization light,this polarized light tends to change the spectrum due to the instability of the light source.In this dissertation,a two-dimensional orthogonal polarized light source is designed with a fiber rocking filter as the core device,so that a common broadband light source can output two beams with orthogonal spectra and orthogonal polarization directions.These two beams compensate each other in spectral intensity.They also have the effect of filtering.The change of one beam can be measured by the change of another beam.The rocking filter has been in depth studied in the dissertation.By exploring the basic principle of the rocking filter and the influence of birefringent fiber,a bimodal and multimodal rocking filter is designed.Based on the rocking filter,a two-dimensional orthogonal polarized light source is built,and a rocking filter manufacturing platform is built.The rocking filter is prepared,and several sources of errors in the preparation process are explored.The research contents of this dissertation mainly include the following aspects:1.Through the research on the fiber rocking filter,the influence parameters of the rocking filter are analyzed,and the sidelobe suppression function of the rocking filter is designed;through the study of different types of birefringent fibers,the spectral characteristics of highorder rocking filter is analyzed.2.Based on the rocking filter,a bimodal filter with an edge hole optical fiber as the carrier is designed through the research on the birefringent fiber dispersion.Based on the research on the phase shift of the rocking filter,a ? phase-shifted bimodal filter is designed.This dissertation introduces two splicing methods of rocking filters,and designs multi-peak rocking filters by splicing and series.Using these two filters as core devices,a two-dimensional orthogonal light source is designed.3.A rocking filter fabrication platform is built.The period length error and the angular rotation error during the preparation of the rocking filter are analyzed.Next,the impact of the angle and the length change,as well as the loss of the melting region and on spectra are analyzed.Last,a rocking filter is made,and its spectrum is analyzed.