Research On Filter Based On MEMS

As a key component of the Dense Wavelength Division Multiplexing (DWDM)System, the tunable optical filter can select specific wavelength out of the multiplewavelengths. With the development of the DWDM technology, a single fiber carriesmore and more wavelengths and the bit rate of the single channel continuouslyincreases. The DWDM systems are developing as intelligent all optic communicationnetwork with the dynamic route.The DWDM system requirements of tunable optical filter, will be more and morehigh, in addition to a large tunable range, to have excellent filtering characteristics,channel crosstalk is very small, the key is the lowest cost. Due to the tunable filter cannot only reduce the size and complexity of the system, and can meet the requirementsfor communication protocol multiplexing, and therefore tunable filter design hasbecome one of research hotspots in recent years. Current tunable optical filtertechnology, there are mainly type acousto-optic tunable optical filter (AOTF), arraywaveguide grating (AWG) tunable optical filter, Fabry-Perot cavity (F-P) type oftunable optical filter, fiber Bragg grating tunable optical filter and so on. These keytechnologies have their own characteristics, but can’t meet the larger tunable range,low cost, low crosstalk, passband ceiling and polarization insensitivity andtemperature requirements, so have limitations in practical project application.Based on the MEMS mirror combination of diffraction grating tunable filter asthe main object of study, based on the optical properties of the optical components,the various characteristics of diffraction grating has carried on the detailed analysis,obtained in spectral expansion after the laws of light. By MEMS reflection after thereceiving power of the single point detector algorithm research, design andpreparation of the tunable filter. Experiments prove that the result can meet the designthe required index. Main work and conclusions and innovations are as follows:Using small size MEMS mirror and diffraction grating, and using only a singledetector is complete different wavelength band power detection.By MEMS mirror, making the light through the grating spectral twice, toenhance spectral resolution and reduce the bandwidth.