Fig. 1. (a) Schematic diagram of the ASL system based on reflective MDOE with the IA-VCSEL array; (b) prototype model for AR/VR smart glasses for eye movement tracking based on the proposed method.

Fig. 2. Schematic diagram of the proposed SOI reflective MDOE unit-cell based on (a) propagation phase and (b) PB phase; distributions of (c) reflection coefficient and (d) reflection phase of the unit cell based on propagation phase; (e) reflection coefficients and discretized phase distributions of the selected unit cells.

Fig. 3. (a) LIV curve of single VCSEL aperture of the IA-VCSEL array; (b) wire bonding of the IA-VCSEL array; (c) assembled PCB of the IA-VCSEL array; (d) infrared images of laser spot pattern encoding using IA-VCSEL arrays.

Fig. 4. (a) Far-field distribution simulations of the designed random/pseudo-random speckle patterns. SEM images of fabricated MDOE: (b) side view of the nanorods; (c) and (d) top view of the MDOE designed by propagation phase and PB phase, respectively; (e)–(g) 3D perspective of (b) to (d), respectively.

Fig. 5. (a) Experimental setup schematic for ASL system verification. (b) Measured far-field infrared images of ASL.

Fig. 6. Calibrated unique distances of SL generated by (a) a single VCSEL and (b) and (c) 2×3 and 3×3 IA-VCSEL arrays; and (d) schematic diagram of calibrated unique distances of N×M IA-VCSEL array.

Fig. 7. Feature pattern extraction corresponding to scenarios with (a) N=6, k=2; (b) N=6, k=4.

Fig. 8. Selected speckle for image matching generated by the (a) single VCSEL and (b) IA-VCSEL array; speckle image matching results by the (c) single VCSEL and (d) IA-VCSEL array; (e) and (f) corresponding correlation coefficient distributions of (c) and (d), respectively.

Fig. 9. (a) Experimental setup schematic for object depth detection; far-field infrared images measured at depth differences of (b) 5 mm and (c) 25 mm; exacted (d) average length L¯ of feature points and (e) area S of feature patterns.

Fig. 10. Measured and fitted curves of (a) L¯ and (b) S as a function of depth difference; (c) error curves of L¯ and S as a function of depth difference.