Fig. 1. Schematics of focusing of incident laser after passing through scattering medium by modulating wavefront. (a) Random speckle formed by plane wave passing through scattering medium; (b) focal spot formed at specific position by modulated incident laser passing through scattering medium

Fig. 2. Flow chart of unit phase modulation using continuous sequential algorithm. M represents segment under modulating, O represents segment without phase modulation, and B represents segment after optimization

Fig. 3. Schematic of experimental setup

Fig. 4. Scattering medium samples with different thicknesses

Fig. 5. Images of random speckles formed by unmodulated incident laser passing through scattering media with different thicknesses. (a) 50 μm; (b) 100 μm; (c) 150 μm; (d) 200 μm; (e) 250 μm

Fig. 6. Focused spots produced by phase-modulated laser passing through scattering media with different thicknesses. (a) 50 μm; (b) 100 μm; (c) 150 μm; (d) 200 μm; (e) 250 μm

Fig. 7. Phase patterns of incident laser wavefront used for generating focal spots which are shown in Fig. 6(a)-(e). (a) 50 μm; (b) 100 μm; (c) 150 μm; (d) 200 μm; (e) 250 μm

Fig. 8. Enhancement factor of intensity at focal point as a function of thickness of scattering medium