Fig. 1. Scheme of the COACH system used as a platform for OCTISAI.

Fig. 2. Laboratory setup of OCTISAI. CPM, coded phase mask; L0 and L1, refractive lenses; QPM, quadratic phase mask; P1 and P2, polarizers.

Fig. 3. Schematic of the GSA for synthesizing a set of CPMs.

Fig. 4. Modulation transfer functions (MTFs) plotted for different aperture sizes, different SLM-sensor gaps, and various imaging systems. MTF profile of (a) square aperture of (D/8)×(D/8) COACH with zh/f2=0.4, (b) synthetic aperture (SA) with zh/f2=0.4, (c) SA with zh/f2=0.5, (d) limited aperture of (D/8)×(D/8) direct imaging with zh=f2, (e) full aperture of D×D COACH with zh=f2, and (f) full aperture of D×D direct imaging with zh=f2; the semitransparent contour shows the MTF of the coherent direct imaging system with D×D aperture and zh=f2. zh is the distance between the imaging aperture and an optical sensor.

Fig. 5. Scheme of OCTISAI for calculating the system bandwidth.

Fig. 6. Tabletop experimental setup for OCTISAI with far-field illuminated objects and components assembled inside the blue rectangle to execute the operation of OCTISAI. BS1 and BS2, beam splitters; CMOS camera, complementary metal-oxide-semiconductor camera; L01, L02, and L1, refractive lenses; LED1 and LED2, identical light-emitting diodes; P1 and P2, polarizers; SLM, spatial light modulator; and USAF, United States Air Force resolution target.

Fig. 7. Holograms of limited aperture of 135×135  pixels: (a₁)–(a₃) point spread holograms (PSHs) and (c₁)–(c₃) object holograms, (b₁) magnitude and (b₂) phase of the final PSH, (d₁) magnitude and (d₂) phase of the final object hologram; full aperture holograms: (e₁)–(e₃) PSHs and (g₁)–(g₃) object holograms, (f₁) magnitude and (f₂) phase of the final PSH, (h₁) magnitude and (h₂) phase of the final object hologram; limited aperture images: (i) COACH and (j) direct imaging; full aperture images: (k) COACH and (l) direct imaging. The subscripts 1, 2, and 3 represent holograms recorded for phase values 0, 2π/3, and 4π/3, respectively.

Fig. 8. OCTISAI: (a) magnitude and (b) phase of the complete mosaic of the PSH, (c) magnitude and (d) phase of the object holograms, obtained from 64 limited apertures; reconstructed images after stitching of (e) eight central horizontal holograms, (f) eight central vertical holograms, (g) 2×2 central holograms, (h) 4×4 central holograms, (i) 6×6 central holograms, and (j) full 64 holograms; (k) MSE of OCTISAI reconstructed images versus the number of subapertures.

Fig. 9. COACH, OCTISAI, and DI images with visibility curve at the bottom for (a) limited aperture COACH with zh=f2/2.5, (b) synthetic aperture (SA) with zh=f2/2.5, (c) SA with zh=f2/2, (d) limited aperture direct imaging with zh=f2, (e) full aperture COACH with zh=f2, and (f) full aperture direct imaging with zh=f2; f2=25  cm.

Fig. 10. (a₁)–(a₈) Phase maps of coded phase masks (CPMs) and (b₁)–(b₈) the respective reconstructed images by OCTISAI, while implementing SA with scattering degrees, σ, from 0.046 to 0.648; (c) SNR and visibility plots versus σ for (b₁)–(b₈).