Research On Several Design Problems Of Deep-Etched Concave Diffraction Grating Wavelength Division Multiplexers

Deep-Etched concave Diffraction Grating (EDG) is considered the most promising solution to narrower channel space and more channel numbers Multi/Demultiplexers in future. Several design problems, including definition of facet positions, flattened spectral response design and vectorial simulation technology, etc., are discussed in this dissertation.Combining the concept of grating constraint equations with Newton Recursive Algorithm, a design algorithm for grating parameter is presented, which is named " Newton Recursive Algorithm for Grating Constraint Equations (NRA-GCE)". A series of grating structure, such as anstigmatic mounts, flat-field receiver mounts, interleaved grating mounts and multiorder mounts, besides Rowland mounts, can be designed by the algorithm. Specially, some three-dimension grating structure can also be designed, such as Arrayed Waveguide Grating (AWG) and free space spectrometer. Based on the interleaved gratings designed by the NRA-GCE, a theory of flatten spectral response named "multi-focal-point method " is studied. Two and three-focal-point mounts are analyzed in detail, and they are the basis of other multi-focal-point mounts design. Through the design and simulation of several typical mounts, the conclusion is drawn that multi-focal-point interleaved gratings have the character of flattened spectral response and widened 3dB bandwidth. A practical Bidirectional Beam Propagation Method (B-BPM) technology for reflective waveguide integrated devices is studied based on a multiple dielectric interface model. And a simulation scheme for EDG is presented through the combination of B-BPM and Angle Spectral theory. In order to test the feasibility and validity of the practical B-BPM technology, two typical devices are designed and simulated. Finally, two kind of Wavelength Division Multiplexer prototype based on EDG and AWG respectively is tested and analyzed.