90 degrees space optical mixer units of folded form

The utility model belongs to the optical communication field relates to a 90 degrees space optical mixer units of folded form. The device mainly comprises crystal (11), polarization splitting prism (6), isosceles prism (14), fourth wave plate (10, 12), half wave plate (9) and isosceles right -angle prism (5, 13, 15). Utilize crystal birefringence beam split principle, realize the relevant mixing in pilot light (7) and local oscillator light (8), output four ways coherent light (1, 2, 3, 4) after the mixing. The utility model discloses mainly be applied to spatial coherence laser communication receiving system.