Intracavity measurement of liquid crystal layer thickness by wavelength tuning of an external cavity laser diode.
The gap of a planar-aligned liquid crystal (LC) cell is measured by a novel method: Monitoring the change in output wavelength of an external-cavity diode laser by varying the voltage driving the LC cell placed in the laser cavity. This method is particularly suitable for measurement of LC cells of small phase retardation. Measurement errors of +/-0.5 % and +/-0.6 % for 9.6-microm and 4.25-microm cells with phase retardations of 1.63 microm and 0.20 microm respectively are demonstrated.
Lan
Yu-Ping
YP
Lin
Yea-Feng
YF
Li
Yu-Tai
YT
Pan
Ru-Pin
RP
Lee
Chao-Kuei
CK
Pan
Ci-Ling
CL