To achieve the high accuracy correction of the distorted wavefront
dynamic phase response characteristic between different grey levels of liquid crystal wavefront correctors (LC WFCs) was investigated. First
a scheme was given to measure the response time and phase modulation of the LC WFC. Then
the fall and rise time of a LC WFC were measured between 0 and 255 grey levels. The results indicate the rise and fall time are 7ms and 11ms respectively. To assure the correction accuracy
the phase modulation curves were cut off with error of λ/10 (λ=633nm) and then the rise and fall time were reduced to 4ms and 6.8ms respectively. At last
the dynamic response time
which is produced with every other grey levels go up to 255 grey level and the reverse process
was measured. The measured results show that the rise and fall time of the grey levels vary at the range of 2ms-5.2ms and 3.7ms-8.7ms respectively. Simultaneously
the switching time between the grey level of 150 and 255 is shortest for both of the rise and fall time
and the response time is longest for the grey levels which is adjacent to 255 grey level. Furthermore
the response time of the grey levels nearby 255 grey level is larger than the response time between 0 and 255 grey level. Therefore
to assure the accurate correction of the wavefront
the response time of the LC WFC should be selected with the longest switch time among the grey levels which is adjacent to 255 grey level.