Fig. 1. Schematic illustration of light propagation in scattering media (using biological soft tissue as an example)^[1]

Fig. 2. Principle of optical focusing through scattering media^[18]. (a) Plane wave scatters after passing through scattering media, forming a speckle pattern; (b) modulated light field is refocused after passing through the same scattering media

Fig. 3. Schematic diagram of feedback-based wavefront shaping experimental setup (HeNe represents helium-neon laser, M represents mirror, λ/2 represents half-wave plate, λ/4 represents quarter-wave plate, BS represents 50% non-polarizing beam splitter, SLM represents spatial light modulator, P represents polarizing mirror, S represents scattering medium, and CCD represents camera)^[18]

Fig. 4. Experimental demonstration of scattered light focusing using feedback-based wavefront shaping^[18]. (a) Transmitted intensity distribution under plane wave illumination;(b) focusing scattered light to a single point using wavefront shaping, with an enhancement factor of approximately 1000; (c) focusing scattered light to five discrete points using wavefront shaping, with an enhancement factor of approximately 200; (d) phase map used to generate the result in Fig. 4(c)

Fig. 5. Imaging results of fly wings through scattering medium^[43]. (a) Direct photoacoustic imaging result under uniform illumination; (b) direct photoacoustic imaging result under random speckle illumination; (c) high-resolution photoacoustic imaging result obtained by scanning focus point after optimization through wavefront shaping

Fig. 6. Schematic diagram of the experimental setup for wavefront shaping based on the transmission matrix (L represents lens, SLM represents spatial light modulator, D represents aperture, P represents polarizer, CCD represents camera)^[55]

Fig. 7. Experimental demonstration of wavefront shaping based on the transmission matrix for focusing scattered light^[55]. (a) Example of transmitted intensity distribution under plane wave illumination; (b) focusing light to a single point using wavefront shaping;(c) normalized focusing operator; (d) focusing light to three discrete points using wavefront shaping

Fig. 8. Experimental results of wide-field imaging of objects hidden behind scattering media using wavefront shaping based on transmission matrix^[55]. (a) Image of a single object; (b) image of two objects

Fig. 9. Principle of wavefront shaping based on optical phase conjugation^[91]. (a) Forward scattering process; (b) backward propagation of phase-conjugated light

Fig. 10. Schematic diagrams of digital optical phase conjugation device^[93]. (a) Measurement steps of scattered light; (b) modulation steps of scattered light

Fig. 11. Principle of focusing light inside a scattering medium using ultrasonic guided stars. (a) In the wavefront measurement step, only the light tagged by ultrasound is measured through frequency selection; (b) in the wavefront modulation step, optical phase conjugation is applied only to the light tagged by ultrasound

Fig. 12. Digital optical phase conjugation method combining ultrasonic guided stars used for fluorescence imaging in scattering media^[123]. (a) Schematic of the imaging process; (b) clear image before embedding in the scattering medium; (c) direct imaging result after embedding in the scattering medium, where features become indistinguishable; (d) point scanning imaging result after wavefront shaping; (e) clear image of the tumor before embedding; (f) direct imaging result of the tumor after embedding; (g) point scanning imaging result of the tumor after wavefront shaping