This paper describes a parallel, highly uniform two-photon lithography approach, facilitated by a digital mirror device (DMD) and a microlens array (MLA). The method allows for the creation of thousands of individually controlled, femtosecond (fs) laser focal points with tunable intensities. In the experiments, the parallel fabrication process utilized a 1600-laser focus array. The focus array's intensity uniformity impressively reached 977%, showcasing a pinpoint 083% intensity-tuning precision for each focal point. A uniform grid of dots was fabricated to showcase the concurrent production of sub-diffraction-limited features. These features are below 1/4 wavelength in size or 200nm. The multi-focus lithography approach holds the promise of enabling swift production of sub-diffraction, intricately designed, and extensive 3D structures, boasting a fabrication rate three times faster than conventional methods.

Low-dose imaging techniques are vital across a range of fields, including materials science and biological engineering. Low-dose illumination safeguards samples from phototoxicity and radiation-induced damage. Nevertheless, low-dose imaging is significantly impacted by the combined effects of Poisson noise and additive Gaussian noise, thus severely degrading image quality metrics like signal-to-noise ratio, contrast, and resolution. We propose a low-dose imaging denoising strategy, implemented through a deep neural network that incorporates a noise statistical model. In lieu of distinct target labels, a single pair of noisy images is employed, and the network's parameters are refined using a noise statistical model. The proposed method's efficacy is assessed through simulation data acquired from optical microscopes and scanning transmission electron microscopes, operating under various low-dose illumination scenarios. Our innovative optical microscope was designed for the capture of two noisy measurements of the same dynamic information, enabling simultaneous acquisition of two images with independently and identically distributed noise. With the help of the proposed method, the biological dynamic process under low-dose imaging conditions is executed and reconstructed. The proposed method's performance on optical, fluorescence, and scanning transmission electron microscopes was experimentally verified, resulting in improved signal-to-noise ratios and spatial resolution in the reconstructed images. We project the broad adaptability of the proposed method to various low-dose imaging systems, spanning biological and material sciences.

Quantum metrology offers a remarkable improvement in measurement precision, exceeding the boundaries of classical physics' capabilities. A photonic frequency inclinometer, based on a Hong-Ou-Mandel sensor, is showcased for exceptionally precise tilt angle measurements across a wide range of tasks, encompassing mechanical tilt determination, the monitoring of rotational/tilt dynamics in light-sensitive biological and chemical entities, and advancing the efficacy of optical gyroscopes. Color-entangled states with a larger difference frequency, combined with a broader single-photon frequency bandwidth, are demonstrated by estimation theory to lead to improved resolution and sensitivity. By building upon Fisher information analysis, the photonic frequency inclinometer adaptively identifies the optimal sensing point, regardless of experimental nonidealities.

While the S-band polymer-based waveguide amplifier's construction is complete, a major impediment remains: boosting its gain performance. Employing energy transfer between various ions, we effectively boosted the efficiency of Tm$^3+$ 3F$_3$ $ ightarrow$ 3H$_4$ and 3H$_5$ $ ightarrow$ 3F$_4$ transitions, leading to heightened emission at 1480 nm and improved gain in the S-band. The polymer-based waveguide amplifier's maximum gain at 1480nm reached 127dB when doped with NaYF4Tm,Yb,Ce@NaYF4 nanoparticles, demonstrating a 6dB improvement over prior studies. Infiltrative hepatocellular carcinoma Our research results underscored the significant impact of the gain enhancement technique on S-band gain performance, providing a framework for optimizing gain across other communication bands.

Inverse design, though useful for producing ultra-compact photonic devices, encounters limitations stemming from the high computational power needed for the optimization processes. Stoke's theorem demonstrates a correspondence between the total change at the external boundary and the summed change across internal segments, thus enabling the decomposition of a complex device into simpler constituent parts. Hence, we integrate this theorem into the methodology of inverse design, developing a novel approach to optical device design. Compared to traditional inverse design methods, the localized regional optimizations yield a significant reduction in computational load. A five-fold reduction in computational time is observed when compared to optimizing the whole device region. Experimental validation of the proposed methodology is achieved through the design and fabrication of a monolithically integrated polarization rotator and splitter. By means of polarization rotation (TE00 to TE00 and TM00 modes) and power splitting, the device delivers power according to the intended ratio. An average insertion loss, as demonstrated, is less than 1 dB, whereas crosstalk remains significantly below -95 dB. These findings highlight the new design methodology's potential for achieving multiple functions on a single monolithic device, as well as its inherent strengths.

Experimental findings concerning a novel FBG sensor interrogation method, based on an optical carrier microwave interferometry (OCMI) three-arm Mach-Zehnder interferometer (MZI), are presented. Our sensing approach capitalizes on a Vernier effect, achieved by superimposing the interferogram created when the middle arm of the three-arm MZI interferes with the sensing and reference arms, boosting the system's sensitivity. The OCMI-based three-arm-MZI's simultaneous interrogation of the sensing fiber Bragg grating (FBG) and the reference FBG offers a perfect solution to cross-sensitivity issues, such as those encountered with other systems. The Vernier effect, produced by cascading optical elements in conventional sensors, is influenced by the relationship between temperature and strain. Strain-sensing experiments demonstrate the OCMI-three-arm-MZI based FBG sensor possesses a sensitivity 175 times greater than that of the two-arm interferometer based FBG sensor. A noteworthy decrease in temperature sensitivity occurred, changing from 371858 kilohertz per degree Celsius to 1455 kilohertz per degree Celsius. The sensor's notable strengths, including its high resolution, high sensitivity, and minimal cross-sensitivity, underscore its potential for precise health monitoring in demanding environments.

Our investigation concerns the guided modes within coupled waveguides, constituted of negative-index materials lacking both gain and loss. Our analysis reveals a connection between non-Hermitian effects and the existence of guided modes, contingent on the structural geometry. The non-Hermitian effect, demonstrating variance from parity-time (P T) symmetry, can be understood through a straightforward coupled-mode theory predicated on anti-P T symmetry. An examination of exceptional points and the slow-light effect is undertaken. The potential impact of loss-free negative-index materials on non-Hermitian optics research is the focus of this study.

Mid-IR optical parametric chirped pulse amplifiers (OPCPA) are explored regarding dispersion management to generate high-energy few-cycle pulses beyond the 4-meter mark. The practical implementation of adequate higher-order phase control is hindered by the pulse shapers present in this spectral region. By employing DFG driven by the signal and idler pulses of a mid-wave-IR OPCPA, we introduce alternative mid-IR pulse shaping techniques, namely a germanium prism pair and a sapphire prism Martinez compressor, to generate high-energy pulses at 12 meters. Cryogel bioreactor Moreover, we investigate the boundaries of bulk compression in silicon and germanium for multi-millijoule pulse energies.

A super-oscillation optical field is used in a new foveated, local super-resolution imaging method. The construction of the post-diffraction integral equation for the foveated modulation device is the first step, followed by the establishment of the objective function and constraints, leading to the determination of the optimal structural parameters of the amplitude modulation device using a genetic algorithm. Secondly, the solutions to the data were inputted into the software for an examination of the point diffusion function. Our research into the super-resolution performance of different types of ring band amplitudes indicated that the 8-ring 0-1 amplitude type presented the strongest performance. The experimental apparatus, built according to the simulation's specifications, loads the super-oscillatory device's parameters onto the amplitude-type spatial light modulator. The resultant super-oscillation foveated local super-resolution imaging system delivers high image contrast throughout the entire viewing field and enhances resolution specifically in the focused portion. Eeyarestatin 1 ic50 The outcome of this method is a 125-fold super-resolution magnification within the foveated visual field, effectively achieving super-resolution imaging of the local field while maintaining the resolution elsewhere. Our system's feasibility and effectiveness are confirmed by experimental verification.

This study experimentally validates a four-mode polarization/mode-insensitive 3-dB coupler design, centered around an adiabatic coupler. The initial two TE and TM modes are successfully integrated within the proposed design. The coupler's performance, evaluated across a 70nm optical bandwidth from 1500nm to 1570nm, shows an insertion loss not exceeding 0.7dB, with crosstalk limited to a maximum of -157dB and a power imbalance of no more than 0.9dB.