A novel optical filter for removing bright-background using an enhanced bacteriorhodopsin thin film

We found, that the bacteriorhodopsin (bR) film has a special property of complementary suppression modulated transmission (CSMT). The yellow and the blue beams can be suppressed mutually when both the beams illuminate the bR film simultaneously. When the blue beam carrying an image with a bright-background noise illuminates on the bR film and then a yellow beam with uniform intensity distribution illuminates the same area, the bright-background can be removed due to the CSMT. In our demonstration, the pattern model is letters "VLSI" with ground noise of small words and the ground noise is removed from the pattern by the new optical filter.