The invention discloses a full-automatic
light wave length measuring method and device. According to the method, the raster dispersion light splitting principle is mainly used, according to the Fraunhofer
diffraction theory, when a parallel
light beam is projected to a raster plane, light
waves can be diffracted at each slot,
diffraction light at all the slots are interfered with each other, when
diffraction angles meet a raster equation, light in the diffraction angle directions can be overlaid to be enhanced, and light in other directions can be counteracted. Through constant rotating speed, the angles of emit-in light on a raster are continuously changed in a circulation mode, light with different wave lengths in the emit-in light can be screened out in sequence, finally,
light intensity is converted to currents according to the
photoelectric effect, and accordingly the wave length of the light screened at this time by the raster and the corresponding currents can be detected. The device is simple in structure, low in manufacturing cost, strong in universality and reliable and stable in working, test condition
parameter control is accurate, the device can be used for full-automatic detection on the wave length of homogeneous light in the
ultraviolet band, the
visible band and the
infrared band, and the device can also be used for detecting the wave length range contained by polychromatic light and corresponding intensity of light
waves with various wave lengths.