Microwave cavity technique to study the dielectric response in 4′-n-Heptyl-4-biphenyl nematic liquid crystal at 20.900 GHz and 29.867 GHz

The experimental studies of the dielectric response in liquid crystal at different temperatures have been done by using a microwave cavity spectrometer. The Microwave Cavity Spectrometer has been used to measure and compare the relative shift, width and amplitude of the resonance profile for the sample loaded in the cavity operated in TM010 mode at two different frequencies 20.900 GHz and 29.867 GHz. The comparative study of dielectric loss, and relaxation time of above liquid crystal at different frequencies has also been done at different temperatures. The method is used for its inherent accuracy and requirement of minute quantity of sample. Importance of nematic liquid crystal for infiltrating photonic crystal fibers for modification of their properties is indicated.