Research of adjustable-bandwidth optical filter

In order to study adjustable-bandwidth optical filters,the variation of Bragg reflection bandwidth induced by electric field in cholesteric liquid crystal(CLC) was measured and analyzed.Experimental results showed that field-induced reorientation might happen when the applied electric field reached a threshold value.The pitch of CLC became gradient along the axis under the combine restriction of applied electric field and boundary condition of liquid crystal cell and the bandwidth was broadened with the input voltage,based which adjustable optical filter can be manufactured.