光学学报, 2011, 31 (10): 1005003, 网络出版: 2011-09-16
平面全息光栅刻线密度的倍频式调整方法
Method of Adjusting the Groove Density Spatial Frequency Multiplication of Plane Holographic Grating
摘要
刻线密度准确与否直接影响光栅色散及给定波长的衍射方向,进而影响光谱仪器结构设计。为了提高全息光栅刻线密度的制作精度,提出了平面全息光栅刻线密度的倍频式调整方法。将给定刻线密度的基准光栅放在干涉场曝光区域内,调节光束干涉角,干涉场曝光光束经基准光栅衍射后,根据调整光栅刻线密度的不同选择不同的衍射级次相互叠加形成莫尔条纹,以基准光栅刻线密度的倍数来确定待制作光栅的刻线密度。理论证明了基准光栅周期与光栅像周期之间存在倍数关系,指出了基准光栅刻线密度选择在倍频式调整方法中的等效规则,分析了基准光栅宽度不同对光栅刻线密度制作精度的影响。计算结果表明,当基准光栅宽度达到100 mm时,制作300 line/mm光栅其刻线密度误差小于1 nm,刻线密度越大误差越小,故以基准光栅的刻线密度来确定待制作全息光栅刻线密度的倍频式调整方法能够满足全息光栅的制作要求。
Abstract
The precision of the groove density influence the dispersion and the diffraction of gratings and the configuration of the spectrograph. In order to improve the precision of the groove density of the plane holographic gratings, a method of adjusting the groove density spatial frequency multiplication of plane holographic grating is proposed. A reference grating with a specific groove density is set in the exposure area. Adjusting the interference angle, different orders of the two diffraction wavefronts match and form Moiré pattern at the screen in a special orientation. The groove desity multiple of the reference gratings can be obtained. The relation between the period of the reference grating and the interference fringe pattern is proved in theory. The equation regulation of the reference grating for groove density alignment is pointed out. The precision relation between the groove density of the interference fringe pattern and the width of the reference grating is also analyzed. The results indicate that the precision of the groove density of adjusting is less than 1 nm at the 100 mm width of the reference grating for 300 line/mm groove density alignment; the error decreases with increasing the width of the reference grating. The method of adjusting the groove density spatial frequency multiplication of plane holographic grating based on the groove density of the reference grating satisfies the fabrication requirement.
韩建, 巴音贺希格, 李文昊, 孔鹏. 平面全息光栅刻线密度的倍频式调整方法[J]. 光学学报, 2011, 31(10): 1005003. Han Jian, Bayanheshig, Li Wenhao, Kong Peng. Method of Adjusting the Groove Density Spatial Frequency Multiplication of Plane Holographic Grating[J]. Acta Optica Sinica, 2011, 31(10): 1005003.