The Research Of Super-resolution Variable Optical Attenuator With DMD

With the rapid growth of the global communication business and business forms, alloptical network has become a major communication network in the21st century. Variableoptical attenuator plays an important role as a passive component in optical communication.Traditional mechanical variable optical attenuators can only meet the general resolutionrequirement of the attenuation, which can not make a great improvement due to the limitationof the mechanical structure. To match the high resolution requirement of the variable opticalattenuator, it is necessary to study a super-resolution variable optical attenuator.The Subject "Study of Super-resolution Variable Optical Attenuator with DMD” is todevelop a new variable optical attenuator with super resolution. The subject establishes a neweffective method for solving the problems about super resolution. The application of thistechnique in WDM is very prospective.The paper begins with the working principle of the traditional variable optical attenuator,and then proposes the technical specifications of the general variable optical attenuator. Twomajor elements in the system, which include the digital micromirror device and the C-Lensfiber collimator, are analyzed in detail. The DMD is analyzed in the mechanical structure,working principle and gray-scale modulation; the coupling loss which is caused by the axial,lateral and angular offset between the two C-Lens Collimator is analyzed based ontransmission matrix and ABCD theorem. The analysis of these two devices has laid a solidfoundation for the optimization of the system design and the improvement of the resolution.In order to analyse the resolution of the system, the paper imitates the optical system withthe ZEMAX optical software, and obtains the average resolution using the previous method, itwill be adjusted according to actual needs.In the final section of the paper, the experiment process is introduced and thecharacteristic tests and experimental study are performed in the major part of thesuper-resolution variable optical attenuator with DMD. And then the coupling loss of the twoC-Lens is tested and contrasted with theoretical simulation values. At last, the attenuation,insertion loss, return loss and polarization dependent loss of the system are analyzed in detail.