Fig. 1. Optical path system of beam expanding collimating

Fig. 2. Image quality evaluation and light spot map of receiving surface

Fig. 3. Mechanical structure of beam expanding collimator

Fig. 4. Collimating beam shear interferogram

Fig. 5. Result of wavefront aberration test

Fig. 6. Preparation of cold atoms in three-dimensional magneto-optical trap

Fig. 7. Time-of-flight signals of cold atom groupsat different throwing height