Fig. 1. Schematic of non-redundant aperture masking technique

Fig. 2. Schematic of closure phase

Fig. 3. Simulation images. (a) Golay-6 sub-aperture distribution; (b) PSF of system; (c) MTF of system

Fig. 4. Closure phase as a function of binary-star contrast ratio and angular separation. (a) Rc=0.1, δA=0.71λ/D; (b) Rc=0.1, δA=1.41λ/D; (c) Rc=0.1, δA=2.12λ/D; (d) Rc=0.01, δA=0.71λ/D; (e) Rc=0.01, δA=1.41λ/D; (f) Rc=0.01, δA=2.12λ/D; (g) Rc=0.001, δA=0.71λ/D; (h) Rc=0.001, δA=1.41λ/D; (i) Rc=0.001, δA=2.12λ/D

Fig. 5. Experimental light path

Fig. 6. Images collected by CCD in experiment. (a) Binary-star image before inserting mask; (b) PSF of system; (c) binary-star image after inserting mask

Fig. 7. Closure phases of point light source in experiment

Fig. 8. Fitting curve of a group of binary-star parameters