Photonic crystal filters have great potential of application in optical communication but a common 2D photonic crystal-based multichannel drop filter is hard to be put into application because the drop efficiency is not high enough. In this paper

we propose two kinds of novel drop filters by putting new structure into common model. One of the novel improved configurations has reflection micro-cavities in the end of waveguide

the other has reflection micro-cavities in two sides of bus waveguide. By analyzing the propagation of light-waves in these structures with finite difference time domain(FDTD) method and giving the schematic diagram of wave propagation

it can be proved that the two novel configurations have capability to decrease the light loss and increase the drop efficiency

obviously. The drop efficiency of the novel filters can achieve 60%~90% theoretically

which is much higher than the level of common filters in drop efficiency of 30%~40%. It is also shows that reflection micro-cavities have great effect on the improvement of the photonic crystal-based filters.