A narrow band-rejection filter based on block copolymers.

We demonstrate filtering characteristics of a polymer band-rejection filter (PBRF) with highly-ordered microphase-separated structure of block copolymers (BCPs). This PBRF is characterized by an Optical Density > 5 blocking at the center wavelength and narrow blocking full bandwidth of 8 nm. Moreover, the wavelength is easily tuned by blending two BCPs with different molecular-weight. A low frequency Raman shift of 200 cm(-1) are, in fact, detected with a sufficient resolution by using this filter in Raman spectroscopy.