The objective of this thesis is to engineer different optical devices based on structuring of the liquid crystals. Initially, we presented various methods to align the liquid crystal molecules and we have detailed the ones which we used during the course of this work. In combination with alignment of liquid crystals we exploited certain physical properties of the liquid crystals to engineer few optical devices. Broadly speaking one can divide these types of devices in three categories viz. Optical filters, spatial modulators and optical waveguides. All three of these devices have an application in telecommunication sector as well as in the other sectors. The structure of cholesteric liquid crystals has a periodic birefringence and gives rise to selective reflection of the circularly polarised light. We exploited these properties to fabricate a switchable Bragg mirror. This Bragg mirror made up of cholesteric liquid crystals was later on used to fabricate switchable and tunable Fabry-Perot interferometer. A polymer network was used to stabilise the cholesteric liquid crystal in order to give the mechanical strength and sustainability to the electric fields. The ferroelectric liquid crystals have very pertinent electro-optical properties especially the response times. This property was exploited to fabricate optical shutters for 3D active glasses based on ferroelectric liquid crystals. Although, the response times for these liquid crystals are higher than nematics, they have some structural defects. We have proposed a new alignment to technique to overcome such defects. Lastly, we have fabricated the waveguides etched in the liquid crystal polymer. We have patterned the liquid crystal polymer in such a way that we have two different phases of liquid crystal namely isotropic and anisotropic present on the same substrate. Waveguides were etched on such a substrate with two different phases to give rise to the polarisation separator to separate TE mode and TM mode in two different branches of the waveguide.