Lithium niobate (LiNbO3 or LN) is a well-known multifunctional crystal that has been widely applied in various areas of photonics, electronics, and optoelectronics. In the past decade, “ion-cut” become key technique to produce wafer-size, high-quality, sub micrometer-thickness crystalline LiNbO3 thin films, i.e., lithium-niobate-on-insulator (LNOI). With rapid development LNOI technology tremendous progress associated surface structuring engineering techniques over last few years, many novel...

Optical waveguides are far more than mere connecting elements in integrated optical systems and circuits. Benefiting from their high confinement miniaturized footprints, waveguide structures established based on crystalline materials, particularly, opening exciting possibilities opportunities photonic chips by facilitating on-chip integration with different functionalities highly compact Femtosecond-laser-direct writing (FsLDW), as a true three-dimensional (3D) micromachining...

Abstract Rare‐earth (RE) ion doped crystalline materials have a wide spectrum of applications in lasers, amplifiers, sensors, as well classical and quantum information processing. The incorporation RE ions into integrated photonics holds great promise for enriching the designer's toolbox with view to addressing key performance features not available existing photonic integration platforms. RE‐ion‐doped thin‐film LiNbO 3 (also called lithium‐niobate‐on‐insulator, RE:LNOI), which inherits...

Abstract Parity-time (PT) symmetry has been unveiling new photonic regimes in non-Hermitian systems, with opportunities for lasing, sensing and enhanced light-matter interactions. The most exotic responses emerge at the exceptional point (EP) broken PT-symmetry phase, yet conventional PT-symmetric systems these require large levels of gain loss, posing remarkable challenges practical settings. Floquet PT-symmetry, which may be realized by periodically flipping effective gain/loss...

Abstract Recently, all‐dielectric metasurfaces are profoundly exploited to enhance light‐matter interactions, resulting from the high quality‐factor (Q‐factor) optical resonances that based on novel concepts such as bound states in continuum (BIC). Unfortunately, BIC operates at a fixed resonance wavelength and wavevector for specific structure. Here, experimental demonstration of dielectric nonlocal metasurface capable robustly maintaining high‐Q is reported, over broad spectral range,...

We report on the fabrication of depressed cladding waveguide lasers in Nd:YAG (neodymium doped yttrium aluminum garnet, Nd:Y3Al5O12) ceramics microstructured by femtosecond laser pulses. Full control over confined light spatial distribution is demonstrated high contrast waveguides with hexagonal, circular and trapezoidal configurations. The confocal fluorescence measurements reveal that original luminescence features Nd3+ ions are well-preserved regions. Under optical pump at 808 nm, showed...

Chip-integrated whispering-gallery resonators (WGRs) enable compact and wavelength-agile nonlinear optical frequency synthesizers. So far, the most flexible phase-matching technique, i.e., quasi-phase matching, has not been applied in this configuration. The reason is lack of suitable thin films with alternating crystal structure on a low-refractive-index substrate. Here, we demonstrate an innovative method realizing film substrates for matching by field-assisted domain engineering lithium...

Mercury(II) ions (Hg2+) and silver (Ag+) are two of the most hazardous pollutants causing serious damage to human health. Here, we constructed surface-enhanced Raman scattering (SERS)-active nanofibers covered with 4-mercaptopyridine (4-Mpy)-modified gold nanoparticles detect Hg2+ Ag+. Experimental evidence suggests that observed spectral changes originate from combined effect (i) coordination between nitrogen on 4-Mpy metal (ii) molecular orientation (from flatter more perpendicular respect...

Thin-film lithium niobate platform, namely lithium-niobate-on-insulator (LNOI), brings new opportunities for integrated photonics, taking advantages from both outstanding crystalline properties and special structural features. The excellent of LNOI have triggered development a variety on-chip photonic devices light generation manipulation. However, as an indispensable component circuit with full functionalities, the thin-film photodetector lacks in portfolios LNOI-based due to standing...

Topological pumping connects the topological features of a modulated system with its transport behavior. It provides powerful means for robust between distant nodes even in one-dimensional chain, which may find applications wave manipulation and quantum information processing. Here, we experimentally demonstrate an adiabatic scheme, defect state, by introducing Fock photonic lattice, is classical analog Fock-state lattice two-mode Jaynes-Cummings model. Since this always protected energy gap...

The van der Waals (vdWs) heterostructures, with vertical layer stacking structure of various two-dimensional (2D) materials, maintain the reliable photonic characteristics while compensating shortcomings participating individual components. In this work, we combine less-studied multilayer tin selenide (SnSe

In this work, we report on the first, to our knowledge, 2.05-µm laser based femtosecond-laser direct written (FsLDW) Tm,Ho:YLF cladding waveguides. A channel waveguide with a 90-µm diameter “fiber-like” low-index is fabricated in 6 at. % Tm 3+ , 0.4 Ho :LiYF 4 crystal by FsLDW. Pumped Ti:sapphire at 795.1 nm, supports efficient lasing oscillation 2050 nm maximum output power of 47.5 mW, minimum threshold 181 and slope efficiency 20.1%. The impacts cavity conditions polarizations pump light...

Ridge waveguides have been fabricated in Nd:YAG crystals by using ion irradiation and precise diamond blade dicing. Continuous-wave lasers at ~1064 nm realized the ridge through optical pumping 808 room temperature. The guiding structure shows superior lasing performance with respect to planar counterpart a slope efficiency of 43% maximum output power 84 mW.

Miniature laser sources with on-demand beam features are desirable devices for a broad range of photonic applications. Lasing based on direct-pump miniaturized waveguiding active structures offers low-cost but intriguing solution compact light-emitting devices. In this work, we demonstrate novel family three dimensional (3D) microstructures monolithically integrated in Nd:YAG crystal wafer. They produced by the femtosecond writing, capable simultaneous light and manipulation. these guiding...

Optical frequency combs are key to optical precision measurements. While most operate in the near-infrared regime, many applications require at mid-infrared, visible or even ultra-violet wavelengths. Frequency can be transferred other wavelengths via nonlinear processes, however, this becomes exceedingly challenging for high-repetition rate combs. Here, it is demonstrated that a synchronously driven high-Q microresonator with second-order nonlinearity efficiently convert visible, and...

Abstract The 2D layered materials are promising candidates for broadband, low‐cost photodetectors. One deficiency of is the relatively low absorbance light, limiting applications Doping plasmonic nanoparticles into may enhance optical owing to localized surface resonance (LSPR) effect; however, considerable defects be introduced at same time, resulting in certain degradation device performance. Here, a novel design photodetectors with enhanced photoresponsivity by non‐contact (NPs) proposed,...

The edge-to-edge topological transport of the one-dimensional odd-sized Su-Schrieffer-Heeger model plays a crucial role in robust energy transfer and information processing. However, it has not been verified experimentally. Here we report on an experimental demonstration this photonic lattice coupled waveguides. When slowly varying spacings adjacent waveguides, light from leftmost to rightmost channels successfully observed. Moreover, speed efficiency are enhanced considerably by introducing...

Abstract Lithium niobate on insulator (LNOI) is widely recognized as an essential optoelectronic integration platform due to its unique ferroelectric properties and photorefractive effect. However, the wide bandgap weak absorption of lithium limit further application in integrated photodetection field. To address this issue, encapsulating silver nanoparticles within LNOI structure are proposed manipulate light field distribution modified through localized surface plasmon resonance (LSPR)...

Dielectric waveguides are widely recognized as excellent and versatile components for integrated multifunctional photonic chips, thanks to their strong optical confinement capabilities. In this study, we present a novel semi-tapered depressed-cladding waveguide structure, designed fabricated using femtosecond laser direct writing technology. The guiding performance of is systematically analyzed by characterizing its loss characteristics. Leveraging the high gain superior platform,...

Abstract 2D materials, including transition metal dichalcogenides, are attractive for a variety of applications in electronics as well photonics and have recently been envisioned an appealing platform phonon polaritonics. However, their direct characterization the terahertz spectral region, interest retrieving, e.g., response, represents major challenge, due to limited sensitivity typical spectroscopic tools weak interaction such long‐wavelength radiation with sub‐nanometer systems. In this...