Activity

Well-performing crossings are located by means of experimentally varying the coupler parameters. The adiabatic waveguide crossing (WgX) demonstrates increased spectral operating bandwidth and enhanced resistance to manufacturing inconsistencies, as opposed to a standard directional coupler. Two distinct methodologies, encompassing transmission methods and the inclusion of crossings in microring resonators, are employed to determine the insertion loss. Our findings indicate the superior performance of the later method in handling low-loss photonic components. Minimizing insertion loss to 0.18dB (406%) enables high-fidelity performance in NOT operations. The presented WgX showcases a quantum NOT operation possessing a high fidelity of 962%.

The inaugural deep-red laser operation of a heavily europium-doped cesium gadolinium double molybdate crystal with a perfect cleavage is presented. At seventeen, a person’s age. A noteworthy continuous-wave output power of 212 milliwatts was generated by a EuCsGd(MoO4)2 laser, utilizing cleaved single-crystal plates, at 7031 nm (5D0 7F4 transition). Key features included a 301% slope efficiency, a low threshold of 51 milliwatts, linear polarization, and a beam quality factor M2 of 16 to 17. This monoclinic crystal holds potential for use in deep-red microchip lasers.

An integrated micro-cavity optical fiber sensor for temperature and gas pressure is proposed with high sensitivity. Initially, a single-mode optical fiber (SMF) is joined with a capillary segment, and then, polydimethylsiloxane (PDMS), the sensitive material, is introduced into the capillary to form the Fabry-Perot interferometer (FPI). Finally, a femtosecond laser is used to ablate the core of the single-mode fiber (SMF), which results in the formation of a third reflective surface, thus composing two successive Fabry-Perot interferometers. A Vernier effect arises when two FPIs exhibit comparable free spectral ranges. Following the implementation of the sensitive material and Vernier effect dual sensitization, the temperature sensitivity of the sensor reached 1441 nm/°C and its gas pressure sensitivity 11382 nm/MPa. A sensor design employing a fiber Bragg grating, cascaded within the system, enables the simultaneous measurement of temperature and gas pressure and eliminates the occurrence of cross-sensitivity.

A multipolar silicon meta-surface, featuring resonant behavior, is presented numerically. This structure is realized by intercalating oblique slits into silicon patches, which generates an ultra-sharp resonant spectrum through the interaction and hybridization of excited electric and magnetic quadrupoles. A demonstrably high-performance electro-optical modulator displays a spectrally shifted modulation sensitivity up to 1546nm/V. Furthermore, a novel optical sensing method for determining ion solution concentrations, with a detection limit as low as 5.151 x 10^-3, is demonstrated, as another application, to the best of our knowledge. An impactful strategy for the implementation of resonant silicon-based nano-photonics and opto-electronic devices is revealed through these findings.

An all-fiber mode converter enabling the simultaneous creation of multiple high-order core modes is proposed and demonstrated, this converter being realized by integrating a helical long-period grating (HLPG) into a few-mode fiber (FMF) via a femtosecond laser. Helical refractive index modulation is created by the sequential actions of the fiber tracing a spiral path along a three-dimensional translation stage, and continuous irradiation of the core with a highly focused femtosecond laser. Grating inscription pitch adjustment is the key to switching from the LP01 mode to the more complex core modes, like LP11, LP21, LP31, LP02, LP12, and LP41. The HLPGs are instrumental in directly generating first-, second-, third-, and fourth-order orbital angular momentum (OAM) modes, and a single high-diffraction-order HLPG allows for the simultaneous excitation of multiple OAM modes with distinct topological charges. This approach introduces a new method for the implementation of high-integration high-order mode converters, or OAM mode generators.

In a planar multilayer thin film, formed using a phase-transition material, we investigate transient metasurface phenomena instigated by photo-thermal stimulation. Illumination of a thoughtfully designed multilayer, utilizing two obliquely incident, phase-coherent pulsed pumps, creates a temporary, reversible temperature pattern in the phase-transition layer. Due to the periodic modulation of refractive index by interfering pumps, a transient spectral feature, analogous to a Fano resonance, appears and is correlated with a guided-mode resonance. A coupled opto-thermal model is utilized to analyze the transient metasurface’s temporal dynamics and assess its speed and modulation properties. In our investigation employing near-infrared pump pulses with peak intensities approximately 100 megawatts per square centimeter and durations of several picoseconds, the transient metasurface’s characteristic time scale is discovered to be on the order of nanoseconds. bms-387032 inhibitor Phase-transition material films subjected to transient metasurface effects demonstrate a capacity for dynamic control of the Q-factor in photonic resonances, further facilitating light modulation and switching applications.

A single-crystal Fe2+ZnSe gain-switched operation is reported, driven by a coupled-cavity Q-switched Er3+ZrF4 fiber laser. We adopt a continuous-wave Er-doped ZrF4 fiber laser, the cavity of which is coupled to the FeZnSe laser cavity, for this approach. The Er-doped fiber laser’s Q-switching performance was reliable in this case, yielding a gain-switched state within the FeZnSe laser. A 79 kHz repetition rate, a 16-second pulse duration for the Er-doped laser pump, and a 62 nanosecond pulse duration for FeZnSe were observed. Gain-switched FeZnSe’s maximum power output amounted to 63 milliwatts.

Experimental results demonstrate a high-throughput quantum key distribution system, achieving continuous-variable discrete modulation over 80 kilometers of standard single-mode fiber. A 25Gbaud, 16-symbol, two-ring constellation was implemented. Thanks to the use of sophisticated digital signal processing algorithms, the system’s unwanted noise is capably controlled. Optical fiber lengths of 25 km, 50 km, and 80 km yielded secret key rates of 4902 Mbits/s, 1186 Mbits/s, and 211 Mbits/s, respectively, demonstrating a significant 674%, 700%, and 665% improvement over a Gaussian-modulated protocol. The construction of a high-performance, long-range continuous-variable quantum key distribution system with a small constellation size is demonstrably feasible, based on our work.

Deep learning-powered techniques are used to enhance super-resolution structured illumination microscopy (SR-SIM) image quality in wide-field and reduced-image contexts, effectively counteracting photobleaching and phototoxicity challenges. Nevertheless, the reliability of novel structures or observational samples remains a subject of scrutiny when employing these methodologies. A dynamic SIM imaging strategy is presented, characterized by capturing complete raw images initially for generating a keyframe SR image, followed by the acquisition of only wide-field images. A deep-learning algorithm, known as KFA-RET, is devised to reconstruct the SR images that complete the dynamic process. Referring to the keyframe’s arrangement and the persistent temporal order of biological structures, KFA-RET substantially improves the quality of reconstructed super-resolution images, minimizing photobleaching and phototoxicity effects. In addition, KFA-RET exhibits a robust ability to transfer knowledge and observe new structures not present in the training dataset.

By utilizing planar (or slab) waveguides, recent experimental work has showcased the possibility of combining the strengths of diffractive and on-chip photonic information processing devices within a single integrated circuit. This analysis illustrates how 3D Fourier optics’ diffraction formulas are translatable to 2D cases, contingent on a certain range of operation speed values for the devices concerned. This communication, apart from its utility for those engaged in on-chip photonics, offers analytical tools for scrutinizing surface plasmon polaritons, surface waves, and the optical, acoustic, and crystallographic characteristics of 2D materials.

A simple and inexpensive fabrication method for polarization splitters with adjustable separation angles and a controllable active area is presented, founded on polarization holography within tensor theory. Our initial methodology involves the design and construction of two polarization holograms, one for reconstructing waves of p-polarization, and the other for reconstructing waves of s-polarization, respectively. After recording both holograms in the same spot on the recording medium using interference, a polarization splitter was readily available as a result. By varying the interference angle, the separation angles of fabricated polarization splitters are easily adjustable. The active area is also easily adjustable by changing the sizes of the interference beams and the recording medium during the recording process. This method’s dependability and correctness are validated by the experimental results. We anticipate that this research will contribute to the expansion of polarization holography’s applicability across diverse fields.

Deterministic optical manipulation of fluorescent nanodiamonds (FNDs) suspended in fluids is an experimental hurdle to overcome in the context of multimodal biological imaging. Formulating and executing nano-optical trapping methods are integral to this pursuit. This letter showcases the ability of chemically prepared gold nanoparticles and silver nanowires, through the application of a long working distance lens and low-power illumination (532-nm laser, 12 W/m²), to facilitate an opto-thermoelectric force for trapping individual FNDs. Our trapping configuration’s functionality depends on the combined effects of thermoplasmonic fields, originating from individual plasmonic nanoparticles, and the surfactant-aided opto-thermoelectric effect, resulting in a nano-optical trap capable of capturing a single FND, 120 nanometers in size.