TERAHERTZ-BAND OPTICAL FILTER, ITS DESIGNING METHOD, AND ITS MANUFACTURING METHOD

摘要

PROBLEM TO BE SOLVED: To obtain a terahertz-band optical bandpass filter that maintains a high transmittance even when objective frequencies are increased and that has a predetermined attenuation gain, a transmissive band width and an inhibition band, and in particular, a terahertz-band optical filter that is excellent in temperature characteristics and that allows setting a certain transmissive band width in a wide temperature range.;SOLUTION: Cavity layers 1 having an optical path length of n-times of λ/2 (n is an integer of ≥1 ) and made of a low-refractive index medium are arranged in N layers (N is an integer of ≥2 ). The cavity layers 1 are coupled through a single layer of coupling layer 4 having an optical path length of λ/4 and made of a high-refractive index medium, thus forming a multi-cavity structure 30. At both ends of the multi-cavity structure 30, matching layers 40 composed of a high-refractive index layer 2 and a low-refractive index layer 3 each having an optical path length of λ/4 are arranged.;COPYRIGHT: (C)2008,JPO&INPIT