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A single-exposure scheme, empowered by QPEM technology, is projected to enable in vivo UOT imaging, opening doors for diverse medical and biological applications.

Ultracompact terahertz (THz) sources, utilizing recently developed nonlinear plasmonic metasurfaces, were successfully shown to emit relatively strong single-cycle THz pulses after femtosecond laser illumination. Their generation of controlled terahertz wavepackets has shown impressive growth; however, further refinement is needed for optimum overall emission strength. We numerically demonstrate a superior coupling of the pumping laser to the nonlinear metasurface through the implementation of a Bragg-assisted perfect absorber design. This ultimately translates to a growth of the THz signal intensity, by more than ten times. Importantly, we show that this methodology can be harmonized with other independent optimization approaches to achieve a substantial surge in radiated THz power. The improvement in emission is greater than two orders of magnitude compared with prior plasmonic metasurface research.

Optical phased arrays (OPAs) in two dimensions (2-D) are typically characterized by constrained scan ranges and small aperture dimensions. To overcome these limitations, we utilize a non-periodic 3232 grid to expand the beam scanning range, and we also strategically disperse 128 grating antennas across 1024 grid points to reduce the number of array elements. Utilizing the genetic algorithm, the sparse distribution of grating antennas and uneven grid spacings are subjected to optimization. These adopted measures enable a 128-channel two-dimensional optical parametric amplifier, working at 1550 nm, to attain a grating-lobe-free steering range of 5316, a field of view of 2416, a beam divergence of 0.031049 degrees, and a sidelobe suppression ratio of 9 decibels.

We observed a non-quantum chiral structure in a freely operating vertical-cavity surface-emitting laser (VCSEL), exhibiting slight birefringence and dichroism misalignment. Phase diagrams of high resolution reveal the evolution of oscillations in parameter space, varying with misalignment. Unlike a previously reported non-quantum chiral dynamic system confined to closed loops in parameter space, this study demonstrates a distinct example, where the chiral structure resides within open parameter regions. Moreover, a bifurcating analysis elucidates the physical mechanisms underlying the formation of these structures.

To unlock the potential of high-resolution sub-diffraction lithography and high-efficiency large-area nanotexturing, one must understand the formation mechanism of laser-induced periodic surface structures (LIPSS). Employing a tightly focused, rectangular laser beam with diverse shape-polarization orientations, we demonstrate the progression of LIPSS formation, starting from a nanohole seed structure and culminating in high-spatial-frequency LIPSS. Without relying on long-range electromagnetic modes, the formation of LIPSS, governed by the distribution of light intensity, yielded a quantitative agreement between the experimental and modeling outcomes. Experimental evidence and computational analysis definitively showcase the stepwise, deterministic progression of LIPSS evolution. Crucially, this evolution is characterized by a dominant near-field structural enhancement contributing to ripple formation. To disrupt the symmetry of a circularly-shaped focus, a rectangular beam with a 73 aspect ratio was employed. The azimuthal rotation of the focal spot’s orientation and polarization allows visualization of the far-field effect during initial seed structure formation, as well as the interplay between far-field and near-field effects in subsequent structural development.

Quasi-bound states in the continuum (Q-BICs) are a key component in enabling sub-wavelength dielectric resonators to achieve high quality factors (Q-factors). Nonetheless, the Q-BIC resonance condition is overly reliant on the resonator’s geometry, thus hindering its practical, broad-bandwidth generation across a single wafer. Employing the base angle as a structural parameter, the truncated nano-cone resonator effectively supports Q-BIC resonance, boasting a high Q-factor exceeding 150 within a wide spectral range exceeding 100 nm. We foresee that our methodology will elevate the application of Q-BIC resonance in various applications that require broad-spectrum tuning capabilities.

A diode-pumped Yb:YLF laser system, employing chirped-pulse amplification, produces 100 mJ sub-picosecond pulses at a 1 kHz repetition rate, resulting in 100 W average power. A cryogenically cooled 78K, regenerative, eight-pass booster amplifier, seeded by an all-fiber front end, constitutes the laser. A single-grating Treacy compressor, with 89% throughput, shortens the duration of output pulses to 980 femtoseconds. To facilitate multi-cycle THz generation and the pumping of high average power parametric amplifiers, the laser will be employed.

Metrology, spectroscopy, and bio-imaging procedures demand the availability of supercontinuum (SC) sources that are both coherent and homogeneous. Still, the SC generation process is usually a very demanding and intricate one. A genetic algorithm (GA) facilitated a convenient and efficient method that we demonstrated. An objective spectrum demonstrates this algorithm’s capacity to reverse-design the geometry of a fiber or waveguide, while remaining agnostic to the involved non-linear processes. This technique led to the design of a dispersion-managed photonic crystal fiber (PCF) intended for supercontinuum generation at a 1 GHz comb spacing. The calibration of an astronomical spectrograph is achieved by using a 150 fs, 450 pJ, 1050 nm input pulse, which generates a 3dB fluctuation spectrum ranging from 510 to 850 nm.

It has been demonstrated through recent theoretical analysis that Kagome photonic crystals (PCs) display topological characteristics of both first and second order. Employing the topological physics of the Kagome lattice, we experimentally demonstrate a Kagome surface-wave photonic crystal, showing its manifestation in surface electromagnetic waves. The observation of both robust edge modes and in-gap corner modes is contingent upon the protection afforded by first-order and second-order topologies. High transmission through the sharply bent waveguide is a testament to the robustness of edge mode transport. When a triangle-shaped specimen is assembled, the localized corner mode is discernible at the corner containing one detached rod. histamine receptor Mimicking the topological physics of classical wave systems is facilitated by our work, which also suggests a potential use in the design of high-performance photonic devices.

The nanobore fiber (NBF), a promising nanoscale optofluidic platform, is characterized by both its long nanochannel and its unique optical properties. Although NBF’s applications have so far been restricted to its intrinsic fiber design, without incorporating additional features, this differs considerably from the extensive functionalities found in various telecommunications fiber devices, potentially hindering wider adoption. We report, to the best of our knowledge, the first instance of NBF-based fiber Bragg gratings (FBGs) produced either by a femtosecond (fs) laser direct writing process or by an ultraviolet (UV) laser phase mask technique. A UV laser-fabricated FBG was optimized, yielding a high reflectivity of 96.89% and preserving the open nanochannel. The NBF-based FBGs were studied through both temperature variation and the penetration of different liquids, revealing their great potential in the realm of nanofluidic applications.

With its ultrawide dynamic range, optical frequency domain polarimetry (OFDP) provides a distributed measurement approach for rapid determination of polarization crosstalk. However, fluctuations in the laser’s phase, coupled with ambient noise, produce a trade-off between the extent of the measurement and the observable signal range. In this letter, we resolve this predicament through the application of a self-referential, unbalanced Mach-Zehnder interferometer design. The characteristics of long-distance measurements (spanning 98km), a wide dynamic range (reaching 1078dB), exceptionally brief measurement times (2 seconds), and a boosted signal-to-noise ratio mitigating ambient noise are experimentally verified. A long polarization-maintaining fiber can be assessed within a rapidly fluctuating environment using this method.

For quantum information processing, pure single photons and biphotons possessing broad bandwidth correlations are crucial resources. By precisely controlling the diameter of micro/nanofibers (MNF), their dispersion characteristics can be customized, leading to a dynamically adjustable biphoton spectrum. A theoretical examination of single photons in a pure state, and biphotons exhibiting broad bandwidth correlation, is conducted for their generation via degenerate spontaneous four-wave mixing within a MNF system. Within our simulated environment, a single-photon state exhibiting a 99% purity will be theoretically achieved by strategically selecting the pump’s bandwidth and central wavelength in relation to the MNF’s diameter and length. A diameter with negligible curvature at the zero-dispersion wavelength is crucial for a narrow pump bandwidth to effectively create remarkably broadband correlation biphotons; for instance, a MNF diameter of 0.7 meters corresponds to a theoretical full width at half maximum of 473 nanometers. A MNF-based quantum light source’s application in practice is contingent upon technologies that precisely control and measure its diameter. Our theoretical examination will direct the experimental construction of top-tier quantum light sources founded on the MNF principle.

While cameras are fundamental to augmented reality (AR) virtual content creation, their integration with transparent displays has presented a significant and persistent challenge. Attempts to develop see-through cameras have been hampered by the challenge of achieving high resolution and seamless integration with augmented reality interfaces.