Fig. 1. Schematic of transmission filter

Fig. 2. Absorption coefficient and trasmission of different materials

Fig. 3. Transmission of 150 nm Al in visible

Fig. 4. Transmission of Al with different thicknesses

Fig. 5. Preparation of filter

Fig. 6. Al filter sample with mesh supported

Fig. 7. Surface topography of mesh-support filter under microscope

Fig. 8. Comparison between the transmission of ESP and sample

Fig. 9. [in Chinese]

Fig. 10. Comparison between simulated transmission and measured transmission of filter

Fig. 11. XPS survey of the Al film on the surfaces

Fig. 12. Pinholes on the surface of a filter

Fig. 13. Transmission of the filter in visible region