Assembly of beam splitters

An assembly of beam splitters, comprising:

• a roof-prism, comprising a first emitting/receiving surface, a roof surface and a first reflecting surface, when a beam of first wavelength enters the roof-prism through the first emitting/receiving surface, the beam of first wavelength is sequentially reflected by the first reflecting surface, the roof surface and the first emitting/receiving surface and leaves the roof-prism from the first reflecting surface;
• a triangle prism, comprising a second emitting/receiving surface, a second reflecting surface and a total internal reflecting surface, wherein the beam of first wavelength from the roof-prism enters the triangle prism through the total internal reflecting surface, and is sequentially reflected by the second reflecting surface and the total internal reflecting surface and leaves the triangle prism from the second emitting/receiving surface;
• and
• a complementary prism, which is adjacent to the second reflecting surface of the triangle prism, and comprises a third emitting/receiving surface and a fourth emitting/receiving surface;
• wherein a beam of second wavelength enters the complementary prism through the third emitting/receiving surface and passes the second reflecting surface to enter the triangle prism, and then the beam of second wavelength is emitted from the second emitting/receiving surface of the triangle prism by reflecting by the total internal reflecting surface, so that the optical axis of the beam of second wavelength and the optical axis of the beam of first wavelength are coaxial;
• and
• wherein a beam of third wavelength enters the complementary prism through the fourth emitting/receiving surface and passes the second reflecting surface to enter the triangle prism, and then the beam of third wavelength passes the first reflecting surface to enter the roof-prism and is sequentially reflected by the first emitting/receiving surface, the roof surface and the first reflecting surface so as to emit from the first emitting/receiving surface of the roof-prism, so that the optical axis of the beam of third wavelength and the optical axis of the beam of first wavelength are coaxial.