For simultaneous temperature and humidity measurement, a fiber-tip microcantilever hybrid sensor combining a fiber Bragg grating (FBG) and a Fabry-Perot interferometer (FPI) was implemented. Femtosecond (fs) laser-induced two-photon polymerization was utilized in the development of the FPI, which incorporated a polymer microcantilever onto the termination of a single-mode fiber. This configuration demonstrated a humidity sensitivity of 0.348 nm/%RH (40% to 90% relative humidity, at 25°C), and a temperature sensitivity of -0.356 nm/°C (25°C to 70°C, at 40% relative humidity). Employing fs laser micromachining, the fiber core was meticulously inscribed with the FBG's design, line by line, showcasing a temperature sensitivity of 0.012 nm/°C (25 to 70 °C, when relative humidity is 40%). The FBG's ability to discern temperature changes through reflection spectra peak shifts, while unaffected by humidity, enables direct ambient temperature measurement. FBG measurements can be integrated to account for temperature variations affecting FPI-based humidity detection. Consequently, the obtained relative humidity measurement is independent of the full shift of the FPI-dip, allowing the simultaneous determination of humidity and temperature. A key component for numerous applications demanding concurrent temperature and humidity measurements is anticipated to be this all-fiber sensing probe. Its advantages include high sensitivity, compact size, easy packaging, and dual parameter measurement.

A random-code-based, image-frequency-distinguished ultra-wideband photonic compressive receiver is proposed. Altering the central frequencies of two randomly chosen codes over a wide frequency spectrum provides flexible expansion of the receiving bandwidth. The center frequencies of two randomly created codes are, simultaneously, exhibiting a minimal difference. The true RF signal, which is fixed, is differentiated from the image-frequency signal, which is situated differently, by this difference. Due to this concept, our system provides a solution to the limitation of receiving bandwidth found in current photonic compressive receivers. Experiments employing two 780-MHz output channels successfully demonstrated sensing capability within the 11-41 GHz spectrum. The linear frequency modulated (LFM) signal, the quadrature phase-shift keying (QPSK) signal, and the single-tone signal, components of a multi-tone spectrum and a sparse radar-communication spectrum, were both recovered.

The technique of structured illumination microscopy (SIM) offers noteworthy resolution enhancements exceeding two times, dependent on the chosen illumination patterns. Historically, the linear SIM algorithm has been the standard for image reconstruction. This algorithm, unfortunately, incorporates hand-tuned parameters, which may result in artifacts, and it's unsuitable for utilization with sophisticated illumination patterns. Deep neural networks are now part of SIM reconstruction procedures, however, suitable training datasets, obtained through experimental means, remain elusive. Our approach, combining a deep neural network with the forward model of structured illumination, achieves the reconstruction of sub-diffraction images independently of training data. By optimizing on a single set of diffraction-limited sub-images, the resulting physics-informed neural network (PINN) circumvents the necessity of any training set. Simulated and experimental data demonstrate that this PINN method can be applied across a broad spectrum of SIM illumination techniques, achieving resolutions consistent with theoretical predictions, simply by adjusting the known illumination patterns within the loss function.

Fundamental investigations in nonlinear dynamics, material processing, lighting, and information processing are anchored by networks of semiconductor lasers, forming the basis of numerous applications. In contrast, causing the usually narrowband semiconductor lasers to interact within the network demands both high spectral homogeneity and a suitable coupling method. Employing diffractive optics in an external cavity, we demonstrate the experimental coupling of vertical-cavity surface-emitting lasers (VCSELs) in a 55-element array. sociology of mandatory medical insurance Twenty-two of the twenty-five lasers were successfully spectrally aligned, each one connected to an external drive laser simultaneously. Correspondingly, we present the noteworthy inter-laser coupling within the laser array. We thereby demonstrate the largest network of optically coupled semiconductor lasers to date and the first comprehensive characterization of a diffractively coupled system of this kind. Our VCSEL network's promise lies in the high uniformity of its lasers, the strong interplay between them, and the scalability of the coupling technique. This makes it a compelling platform for investigating complex systems and a direct application as a photonic neural network.

Nd:YVO4 yellow and orange lasers, passively Q-switched and diode-pumped efficiently, are constructed with the pulse pumping approach, utilizing intracavity stimulated Raman scattering (SRS) and second harmonic generation (SHG). Employing a Np-cut KGW within the SRS process, a user can choose to generate either a 579 nm yellow laser or a 589 nm orange laser. A compact resonator design, integrating a coupled cavity for intracavity SRS and SHG, is responsible for the high efficiency achieved. The precise focusing of the beam waist on the saturable absorber ensures excellent passive Q-switching. The orange laser, operating at 589 nm, delivers output pulse energy up to 0.008 mJ and a peak power of 50 kW. Another perspective is that the yellow laser at a wavelength of 579 nm can produce a maximum pulse energy of 0.010 millijoules, coupled with a peak power of 80 kilowatts.

The significant capacity and low latency of low Earth orbit satellite laser communication make it an indispensable part of contemporary communication systems. The satellite's overall operational time is heavily influenced by the cyclical charging and discharging patterns of its battery. Low Earth orbit satellites' frequent charging under sunlight is undermined by their discharging in the shadow, a process that results in rapid aging. This research paper delves into the energy-conscious routing design for satellite laser communication, and also presents the satellite aging model. In light of the model, we advocate for a genetic algorithm-driven energy-efficient routing scheme. In contrast to shortest path routing, the proposed method significantly extends satellite lifetime by 300%. The network's performance is negligibly compromised, with a mere 12% increase in blocking ratio and a 13-millisecond increase in service delay.

The extensive depth of field (EDOF) inherent in metalenses provides an increased imaging area, resulting in advanced applications for imaging and microscopy. Despite the presence of limitations, such as an asymmetric point spread function (PSF) and unevenly distributed focal spots, in existing forward-designed EDOF metalenses, which degrades image quality, we propose a novel approach employing a double-process genetic algorithm (DPGA) to optimize the inverse design of EDOF metalenses. Defactinib concentration In employing different mutation operators in consecutive genetic algorithm (GA) runs, the DPGA approach exhibits significant advantages in determining the optimal solution throughout the complete parameter space. In this method, 1D and 2D EDOF metalenses, operating at a wavelength of 980nm, are separately designed, each showing a notable improvement in depth of field (DOF) in contrast to standard focusing methods. Furthermore, maintaining a uniformly distributed focal spot ensures stable longitudinal image quality. Applications for the proposed EDOF metalenses are substantial in biological microscopy and imaging, and the DPGA scheme is applicable to the inverse design of other nanophotonic devices.

Multispectral stealth technology, encompassing the terahertz (THz) band, will assume an ever-growing role in contemporary military and civil applications. Modularly designed, two adaptable and transparent meta-devices were created for multispectral stealth, including coverage across the visible, infrared, THz, and microwave bands. Flexible and transparent film materials are employed in the creation and construction of three fundamental functional blocks for IR, THz, and microwave stealth. By means of modular assembly, involving the addition or removal of covert functional components or constituent layers, two multispectral stealth metadevices can be readily constructed. The dual-band broadband absorption capabilities of Metadevice 1, covering both THz and microwave frequencies, average 85% absorptivity within the 0.3-12 THz spectrum and surpass 90% in the 91-251 GHz frequency range, making it well-suited for THz-microwave bi-stealth applications. Metadevice 2, designed for infrared and microwave bi-stealth, exhibits absorptivity exceeding 90% across the 97-273 GHz spectrum and shows low emissivity of approximately 0.31 within the 8-14 m range. Maintaining their optical transparency, both metadevices retain their superb stealth capabilities under curved and conformal settings. water remediation We have developed an alternative design and manufacturing procedure for flexible, transparent metadevices, enabling multispectral stealth, especially on nonplanar surfaces.

We introduce, for the initial time, a surface plasmon-enhanced dark-field microsphere-assisted microscopy system capable of imaging both low-contrast dielectric and metallic objects. Using an Al patch array as the substrate, we demonstrate improved resolution and contrast in dark-field microscopy (DFM) imaging of low-contrast dielectric objects, in comparison with metal plate and glass slide substrates. 365-nm-diameter hexagonally arrayed SiO nanodots are resolvable across three substrates, exhibiting contrast variation from 0.23 to 0.96. 300-nm-diameter hexagonally close-packed polystyrene nanoparticles, however, are only detectable on the Al patch array substrate. Dark-field microsphere-assisted microscopy offers an avenue for improved resolution, permitting the resolution of an Al nanodot array with a 65nm nanodot diameter and 125nm center-to-center spacing, a distinction beyond the capabilities of conventional DFM.