Weak light collector in three-dimensional space

The utility model relates to an optical device and discloses a weak light collector in a three-dimensional space. The weak light collector comprises an ellipsoidal reflection mirror and a spherical reflection mirror. Both the ellipsoidal reflection mirror and the spherical reflection mirror are concave reflection mirrors, and the concave faces of the two mirrors face each other to form a cavity. The center of the spherical reflection mirror coincides with a focus of the oval in the ellipsoidal reflection mirror. The curvature radius of the spherical reflection mirror is equal to the focal length of the oval in the ellipsoidal reflection mirror. According to the weak light collector, a special structure is employed, and weak light such as fluorescence and Raman scattering light of trace substance emitted by a laser beam is effectively and directionally collected in a three-dimensional space range.