The invention belongs to the technical field of guided wave
optics, and specifically relates to a multi-pass-band and ultra-narrow-band
optical filter based on
prism coupling. The multi-pass-band and ultra-narrow-band
optical filter based on
prism coupling includes a composite transparent body (for short, complex) of a cylinder or a
square cylinder and a
planar optical waveguide, wherein the cylinder or the
square cylinder is
cut in a longitudinal axis by a certain angle; a
planar optical waveguide is prepared on one tangent plane according to the transmission center
wavelength, and is formed by thin films with different
layers and thickness; the two
cutting bodies are fitted and fixed along the tangent plane, and are sealed to form a complex; and the two end surfaces of the complex are each plated with a
broadband reflection reducing
coating. The single or multiple guided mode
waveguide of the multi-pass-band and ultra-narrow-band
optical filter based on
prism coupling can respectively form a plurality of pass bands with ultra narrow bands in the purple light area, the
blue light area, the
green light area and the
red light area in the visible light areas, wherein the half height width of the pass band can achieve the picometer (10-12m) magnitude; and the center
wavelength of each band can realize
fine tuning through change of angle. The filtering energy band in the multi-pass-band and ultra-narrow-band optical filter based on
prism coupling has the advantages of having symmetrical
band shape, being extremely low in the
sideband transmittance, having superb
narrowband property, being easy to be manufactured into a
large aperture device, and being specifically suitable for spectral measurement with high precision.