We present the modelisation. and simulation at wavelengths about 1550nm of a waveguide grating made up of polymer and liquid crystal slices as the core layer and glass as cladding layers. The model combines a matrix-transfer method with a Modal Analysis. The pre-polymerised mixture considered in our calculations is made of NOA61 and 5CB. We derive that the device call behave as either an electrically tuneable narrow notch filter, or a switchable bandpass filter. A tuning range of 7 nm can be obtained for the notch filter with all optical bandwidth at -20 dB less than 1 nm.