The method for measuring the groove density of variable-line-space gratings with elimination of the eccentricity effect.
To eliminate the eccentricity effect, a new method for measuring the groove density of a variable-line-space grating was adapted. Based on grating equation, groove density is calculated by measuring the internal angles between zeroth-order and first-order diffracted light for two different wavelengths with the same angle of incidence. The measurement system mainly includes two laser sources, a phase plate, plane mirror, and charge coupled device. The measurement results of a variable-line-space grating demonstrate that the experiment data agree well with theoretical values, and the value of measurement error (ΔN/N) is less than 2.72 × 10(-4).
National Synchrotron Radiation Laboratory, University of Science and Technology of China, Hefei, China.
Qingbo
Q
Wang
National Synchrotron Radiation Laboratory, University of Science and Technology of China, Hefei, China.
Zhengkun
Z
Liu
National Synchrotron Radiation Laboratory, University of Science and Technology of China, Hefei, China.
Huoyao
H
Chen
National Synchrotron Radiation Laboratory, University of Science and Technology of China, Hefei, China.
Yu
Y
Wang
National Synchrotron Radiation Laboratory, University of Science and Technology of China, Hefei, China.
Xiaolong
X
Jiang
National Synchrotron Radiation Laboratory, University of Science and Technology of China, Hefei, China.
Shaojun
S
Fu