OPTICAL BAND PASS FILTER AND METHOD FOR MANUFACTURING THE SAME

摘要

PROBLEM TO BE SOLVED: To provide an optical band pass filter which can avoid the Fabry-Perot resonance even while unnecessitating the process of polishing a glass plate into a wedge form. SOLUTION: The optical band pass filter is composed of a first parallel flat plate having an antireflection film formed on the upper face and a second parallel flat plate having a band pass filter film formed on the lower face. The filter is obtained by joining the first and second parallel flat plates with an adhesive layer in such a manner that the antireflection film and the band pass filter film form outer faces and that the two film planes form a specified inclination angle.