2 products in this product line


An optical notch filter has a suspension of small absorbing particles which blocks a narrow band of frequencies. The small absorbent particles are suspended as a colloidal system which can either be solid, liquid or gas as host material. The absorbing particles can be incorporated in a solid matrix as a transmission filter or used on the surface of a mirror as a reflection filter. The filter can be tuned by an externally applied electric field or by applying hydrostatic pressure.