Speed and enhancement are the two most important metrics for anti-scattering light focusing by wavefront shaping (WS), which requires a spatial light modulator with a large number of modulation modes and a fast speed of response. Among the commercial modulators, the digital-micromirror device (DMD) is the sole solution providing millions of modulation modes and a pattern rate higher than 20 kHz. Thus, it has the potential to accelerate the process of anti-scattering light focusing with a high enhancement. Nevertheless, modulating light in a binary mode by the DMD restricts both the speed and enhancement seriously. Here, we propose a multi-pixel encoded DMD-based WS method by combining multiple micromirrors into a single modulation unit to overcome the drawbacks of binary modulation. In addition, to efficiently optimize the wavefront, we adopted separable natural evolution strategies (SNES), which could carry out a global search against a noisy environment. Compared with the state-of-the-art DMD-based WS method, the proposed method increased the speed of optimization and enhancement of focus by a factor of 179 and 16, respectively. In our demonstration, we achieved 10 foci with homogeneous brightness at a high speed and formed W- and S-shape patterns against the scattering medium. The experimental results suggest that the proposed method will pave a new avenue for WS in the applications of biomedical imaging, photon therapy, optogenetics, dynamic holographic display, etc.

Effectively prolonging the residence time of nanoprobes in the tumor region and reducing the accumulation of nanoprobes in the vital organs (for example, lung, liver and spleen) is crucial for high-efficiency photodynamic therapy (PDT) of cancer. Herein, we systematically report an ultra-small and highly stable nanoplatform with diameters of 4, 8 and 13 nm that exhibited excellent photodynamic therapeutic efficacy using Fe 3 O 4 @polymer-NPO/PEG-Glc@Ce6 nanoprobes. Based on the small size effect, the nanoprobes displayed lower cytotoxicity and excellent biocompatibility. Owing to the synergistic virtues of markedly active targeting and intrinsic small size effect, the Fe 3 O 4 @P-NPO/PEG-Glc@Ce6 nanoprobes can effectively prolong their residence time in the tumor region and reduce accumulation in the normal organs. Benefitting from the small size effect, the synthesized Fe 3 O 4 @P-NPO/PEG-Glc@Ce6 nanoprobes exhibited excellent tumor-targeting capability and photodynamic therapeutic efficacy by inhibiting the growth of tumors in mice under visible red light irradiation with a relatively lower power. The successful application of the small size effect in Fe 3 O 4 @P-NPO/PEG-Glc@Ce6 nanoprobes to significantly improve the PDT efficiency in our strategy suggests new building blocks for PDT of tumors and paves a new way for clinical therapies and translation in the near future.

Diabetes mellitus (DM) is a chronic disease affecting nearly 400 million people worldwide. In order to manage the disease, patients need to monitor the blood glucose level by puncturing the finger several times a day, which is uncomfortable and inconvenient. We present here a potential non-invasive monitoring method based on the velocity of ultrasonic waves generated in glucose solution by the photoacoustic principal, which can recognize the glucose concentration down to 20mg/dL. In order to apply this method to warm bodies, we carefully designed the experiment and performed measurements from 30 °C to 50 °C to generate a set of calibration curves, which may be used by engineers to build devices. Most importantly, we have theoretically explained the relationship between the compressibility and the glucose concentration. Our results show that the compressibility of solution decreases with the glucose concentration, which clarified the controversy between theory and experiment results in the literature. The derived formula is generally validity, which can be used to nondestructively measure solution concentration for other types of solutions using photoacoustic principle.

A line-structured laser scanner is widely applied for 3D reconstruction in industrial environments with ubiquitous various luminance, complicated background, diverse objects, and instable lasers. These elements will show up as noise in the obtained laser stripe images. Therefore, the basic and key point for a line-structured laser scanner is to accurately extract the laser stripe from noise. This paper proposes an effective laser stripe extraction procedure with two steps. First, a novel laser stripe center extraction method based on the geometry information and correlation in the laser stripe, is designed to significantly eliminate noise and accurately extract the laser stripe centers. In addition, the robustness, speed, and accuracy of this method are respectively analyzed in detail. Second, piecewise fitting is adopted to acquire a smooth and continuous laser stripe centerline. In order to select the optimal fitting method, the characteristics of two spline methods, Akima spline and cubic Hermite spline, are deeply analyzed and compared. Finally, an experiment is carried out by using a rough metal step and a line-structured laser scanning system. The experiment results demonstrate that the proposed self-adaptive convolution-mass method can significantly eliminate noise in industrial environments. In addition, the cubic Hermite spline is a better choice for 3D reconstruction, rather than the Akima spline.

Realizing a high-contrast anti-scattering light focusing by using a spatial light modulation such as a digital micromirror device (DMD) demands a robust optimizer in the process of wavefront shaping. Genetic algorithm (GA) as a common practice can easily be stuck into the inferior local minima. Here, we combined GA with encoding neighboring pixels of DMD to circumvent the inferior local minima. Simulations and experiments have demonstrated that our method could greatly increase the anti-scattering capability when compared with the conventional GA method. This work could be an important step towards deep tissue noninvasive optical imaging, optogenetics, and photodynamic therapy.