用二维全息光栅制作光学时钟分布中的全息光学元件

Fabrication of Holographic Optical Element in Optical Clock Distribution with 2-D Holographic Grating

提出了用二维全息光栅制作自由空间光学时钟分布中的全息光学元件的方法.实验中采用类似于马赫 泽德干涉仪的光路;其中,物光为二维光栅中间的9个衍射级.分析了二维光栅各衍射级的衍射效率、位置及各衍射级之间的间距.初步实验得到了可产生二维3×3输出端的全息光学元件.理论分析表明,该全息光学元件可适用于3×3光敏面半径大于10μm的光探测器阵列.

A method of fabricating holographic optical element (HOE) for free-space optical clock distribution is presented.The optical geometry resembling the Mach-Zehnder interferometer is adopted to record the HOE.The middle nine diffraction orders of a 2-D holographic grating are used as the object light in the recording.Considering the effect of multiple exposures on the diffraction efficiency of hologram,the 2-D holographic grating is formed with two one-dimensional gratings adhering to each other.The grooves of the two gratings are perpendicular to each other.The position of each diffraction order and the spacing between different orders of the 2-D holographic grating are analyzed.The diffraction efficiency of each order is also discussed.HOE with 2-D 3×3 fan-outs has been obtained in primary experiments.It is verified by theoretical analysis that the HOE can perfectly feed a 3×3 array of detectors which have a radius greater than 10 μm.