The overall results demonstrate the effectiveness of the optoelectronic method to produce femtoliter droplets, both with pure water and with aqueous solutions containing biological material.For the first time, to the best of our knowledge, we experimentally demonstrate that multiple-input-multiple-output (MIMO) processing allows using a single photodiode to detect simultaneously a wavelength-division multiplexing (WDM) visible light communications (VLC) signal. The photodiode has a triple junction, and when it is illuminated by a WDM signal, the junctions produce inherently three photocurrents that are unusable for detecting any of the WDM signals. However, by means of linear MIMO processing, we are able to recover the transmitted signals exactly. Bit error rate measurements confirm the effectiveness of the proposed solution. This opens a new scenario for practical WDM-VLC systems.Understanding turbulence effects on laser beam propagation is critical to the emerging design, study, and test of many long-range free space optical (FSO) communication and directed energy systems. Conventional studies make the prevalent assumption of isotropic turbulence, while more recent results suggest anisotropic turbulence for atmospheric channels within a few meters elevation above the ground. As countless FSO systems have been and continue to be deployed in such channels, analysis of anisotropic modelings has become one of the fastest growing areas in FSO research. This in turn motivates new tools that can distinguish anisotropic characteristics to improve both modeling accuracy and physical interpretations. Wavefront sensors such as Shack-Hartmann sensors, interferometers, and plenoptic sensors have been devised and used in experiments; however, they all require rigid alignments that lack resilience against temperature gradient buildup and beam wander. We find that by using a light field camera (LFC) that extracts perturbation of individual light rays, the wave structure function of turbulence can be retrieved with high reliability. Furthermore, we find through experiments that the outer scales of near-ground turbulence tend to be a magnitude smaller than conventional theoretical assumptions, agreeing with new findings by others but being absent in current theoretical modelings. As a result, we believe that the LFC is an ideal candidate in the frontier of turbulence research; it is both commercially available and easy to adapt to turbulence experiments.The thermal quenching effect has been systematically investigated in bismuth (Bi)-doped phosphogermanosilicate fiber with varying thermal conditions. For the first time, to the best of our knowledge, the activation of phosphor-related Bi active center (BAC-P) is achieved by thermal quenching at 400°C with a heating time of 10 min, evidenced by the enhanced luminescence of BAC-P ($\sim1.3$∼1.3 times) at 1300 nm. The experimental results reveal that a relatively low heating temperature with prolonged heating time stimulates the growth of BAC-P, whereas higher operating temperatures ($ \ge 500^\circ $≥500∘C) result in the irreversible destruction of BAC-P. The underlying mechanism for the thermally stimulated BAC-P process is also analyzed and discussed.Here we report a novel, to the best of our knowledge, method of active intracavity intensity modulation for cavity-enhanced photoacoustic spectroscopy (PAS) without the need for any external optical modulators. Based on the Pound-Drever-Hall (PDH) locking technique, a dither is added to the PDH error signal to periodically vary the locking point between the laser frequency and optical cavity within a sub-MHz frequency range. While significantly enhancing the intracavity laser intensity, the optical cavity also acts as an intensity modulator. As a proof-of-principle, we demonstrated the PAS of $\rm C_2\rm H_2$C2H2 by placing a photoacoustic cell ($Q$Q-factor $\sim10$∼10) inside a Fabry-Perot cavity (finesse $\sim628$∼628) and adopting the proposed intracavity intensity modulation scheme.  https://www.selleckchem.com/products/methylene-blue-trihydrate.html  By detecting the weak $\rm C_2\rm H_2$C2H2 line at $6412.73\;\rm cm^ - 1$6412.73cm-1, the sensor achieves a normalized noise equivalent absorption (NNEA) coefficient of $1.5 \times 10^ - 11\;\rm cm^ - 1\rm WHz^ - 1/2$1.5×10-11cm-1WHz-1/2. This method enables the continuous locking of laser frequency and optical cavity, and it achieves the intracavity intensity modulation with an adjustable modulation depth as well.A novel, to the best of our knowledge, approach is developed to realize a high-power compact efficient yellow-lime-green triple-color $\rm Nd\rm YVO_4$NdYVO4 self-Raman laser. The 588 nm yellow laser, the 559 nm lime laser, and the 532 nm green laser are converted from the 1064 nm fundamental wave and the 1176 nm Stokes Raman field. The simultaneous three-color operation is accomplished with three stages to step-by-step generate the 588 nm, 559 nm, and 532 nm lasers by using three different lithium triborate (LBO) crystals. By tuning the temperature of each individual LBO crystal, the 588 nm, 559 nm, and 532 nm output powers can be nearly the same and concurrently up to 2.4 W at the incident pump power of 30 W, corresponding to a conversion efficiency of 24% for the total output power.Frequency comb synthesized microwaves have been so far realized with tabletop systems, operated in well-controlled environments. Here, we demonstrate state-of-the-art ultrastable microwave synthesis with a compact rack-mountable apparatus. We present absolute phase noise characterization of a 12 GHz signal using an ultrastable laser at $\sim194\;\rm THz$∼194THz and an Erfiber comb divider, obtaining $ - 83\;\rm dBc/Hz$-83dBc/Hz at 1 Hz and $ \lt - 166\;\rm dBc/Hz$ less then -166dBc/Hz for offsets greater than 5 kHz. Employing semiconductor coating mirrors for the same type of transportable optical frequency reference, we show that $ - 105\;\rm dBc/Hz$-105dBc/Hz at 1 Hz is supported by demonstrating a residual noise limit of division and detection process of $ - 115\;\rm dBc/Hz$-115dBc/Hz at 1 Hz. This level of fidelity paves the way for the deployment of ultrastable photonic microwave oscillators and for operating transportable optical clocks.