基于体全息技术的波分解复用(WDM)器件研究

为了寻求更高质量和密集度的WDM器件，对体全息技术制作WDM器件的新方法进行了研究。利用耦合波理论讨论了光折变多重体全息光栅作为波长滤波器实现波长解复用的基本原理。通过理论分析得出了最大衍射效率、最佳写入光强比与耦合强度大小的关系表达式。考虑有效电光系数和空间电荷场随写入光路几何组态的变化关系，以及各信道衍射光波长、衍射角等因素对曝光时序的影响，利用递推法推导出更为精确的曝光时序。采用高亮度溴钨灯代替价格昂贵的大功率可调谐激光器作为波长解复用光源，设计出基于体全息技术的16通道波分解复用器的实验方案。理论分析表明，该器件可将波长相隔0.8nm的谱线分开约1.0mm，这有助于实现密集波长的解复用。

Study on the demultiplex of WDM based on volume holographic technology

For getting superior quality and denser WDM device, a new method to make demultiplexing device with volume holographic technology is studied. Based on coupled-mode theory, the fundamental principle that photorefractive volume grating is used as a wave filter for WDM is discussed. The equations of optimum beam ratio, strength of coupling and corresponding maximum diffraction efficiency are described. The effects of the relation on recording geometry with effective electro-optical coefficient and space charge field, wavelength of diffraction beam and diffraction angle on exposure sequence are taken into account, and the perfect exposure sequence is discussed based on recurrence method. A high-luminosity halogen lamp is considered as the multiplex photosource and an experimental scheme of 16 channels wave demultiplex based on volume holographic technology is designed. The device can separate the line which wavelength space out 0. 8 mm to 1. 0 mm distance and fit in demultiplexing for crowed wave.