We propose an idea using a simulated annealing algorithm for amplitude modulation to focus light through disordered media. Using 4096 independently controlled segments of an incident wavefront, the intensity of the target signal is enhanced 73 times over the original intensity of the same output channel. The simulated annealing algorithm and existing amplitude control algorithms for focusing through scattering media are compared experimentally. It is found that the simulated annealing algorithm achieves the highest enhancement when the number of iterations required for optimization is the same.

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The adjustment of the intensity of laser scattering focus with machine learning based on the back propagation (BP) neural network is proposed in this paper. Focus based on 'laser scattering' is more flexible than that based on a lens and imaging based on 'laser scattering focus' can break through the diffraction limit of lens imagingin order to obtain higher resolution. Therefore, knowing how to adjust the scattering focus is very important. In this paper, we used known data to train a BP network, and then used the trained BP network to realize the rapid and arbitrary adjustment of the intensity of the scattering focus. This method has potential application value in the field of 'laser scattering focus'. In addition, with the rapid development of artificial intelligence, machine learning is increasingly being used in various fields, including physics. We hope that machine learning can also be applied to 'laser scattering focus'. Therefore, in this paper, we conducted some preliminary investigations, which could provide reference for further research.

We introduce particle swarm optimization for amplitude modulation to focus light through disordered media. Using 4096 independently controlled segments of incident wavefront, the intensity at the target is 75 times enhanced over the original intensity of the same output channel. The particle swarm optimization and existing amplitude control algorithms of focusing through scattering media are compared in the experiment. It is found that particle swarm optimization achieves the highest enhancement with less time compared with the genetic algorithm.

Electrically tunable metasurfaces can realize two-dimensional pixelated spatial light modulation and have a wide range of applications in optical switching, free-space communication, high-speed imaging, and so on, arousing the interest of researchers. Here, a gold nanodisk metasurface on a lithium-niobate-on-insulator (LNOI) substrate is fabricated and experimentally demonstrated as an electrically tunable optical metasurface for transmissive free-space light modulation. Using the hybrid resonance formed by the localized surface plasmon resonance (LSPR) of gold nanodisks and the Fabry–Perot (FP) resonance, the incident light is trapped in the gold nanodisk edges and a thin lithium niobate layer to realize field enhancement. In this way, an extinction ratio of 40% is achieved at the resonance wavelength. In addition, the proportion of hybrid resonance components can be adjusted by the size of the gold nanodisks. By applying a driving voltage of ± 2.8 V, a dynamic modulation of 135 MHz is achieved at resonant wavelength. The highest signal-to-noise ratio (SNR) is up to 48 dB at 75 MHz. This work paves the way for the realization of spatial light modulators based on CMOS-compatible LiNbO3 planar optics, which can be used in lidar, tunable displays, and so on.