Three-dimensional Photonic Crystals Research Articles

Diamond-lattice photonic crystals assembled from DNA origami.

Colloidal self-assembly allows rational design of structures on the micrometer and submicrometer scale. One architecture that can generate complete three-dimensional photonic bandgaps is the diamond cubic lattice, which has remained difficult to realize at length scales comparable with the wavelength of visible or ultraviolet light. In this work, we demonstrate three-dimensional photonic crystals self-assembled from DNA origami that act as precisely programmable patchy colloids. Our DNA-based nanoscale tetrapods crystallize into a rod-connected diamond cubic lattice with a periodicity of 170 nanometers. This structure serves as a scaffold for atomic-layer deposition of high-refractive index materials such as titanium dioxide, yielding a tunable photonic bandgap in the near-ultraviolet.

Three-Dimensional Photonic Crystals Based on Porous Anodic Aluminum Oxide.

Photonic crystals (PCs) consisting of a periodic arrangement of holes in dielectric media have found success in light manipulation and sensing. Among them, three-dimensional (3D) PCs are in high demand due to their unique properties originating from multiple photonic band gaps (PBGs) and even full ones. Here, 3D PCs based on porous anodic aluminum oxide (AAO) were fabricated for the first time. Our approach involves prepatterning of the aluminum surface by a focused ion beam to form a hexagonal array of pore nuclei. Subsequent anodization in 1 M H3PO3 using a sine wave profile of voltage provides AAO with a defect-free in-plane porous structure and out-of-plane porosity modulation. The ability to tune the position, width, and depth of the PBGs is demonstrated. The combination of the flexibility of the proposed approach with the unique properties of AAO extends the range of practical applications of 3D PCs far beyond the current achievements.

A new strategy for structural color fabrics: Transfer of photonic crystal coatings from slides to fabrics

The construction of three-dimensional photonic crystals on textile surfaces has emerged as a highly effective method to create fabrics with structural color, generating significant interest among researchers. However, the strict requirements of the substrate fabrics and the challenges associated with patterning coatings for bright structural colors have hindered the widespread application of photonic crystal materials in the textile industry. In this study, we present a strategy for obtaining patterned structural color coatings on fabrics made of different materials. Pre-crystallized poly(styrene-methyl methacrylate-acrylic acid) (P(St-MMA-AA)) liquid photonic crystals (LPCs) are used as raw material for the rapid preparation of solid photonic crystals (SPCs). These SPCs with structural colors are used as templates and transferred to various fabrics through transfer printing techniques. Importantly, the SPCs maintain an ordered face-centered cubic structure both before and after transfer. Such a feature ensures that the processed structural color fabrics exhibit vibrant and iridescent structural colors. This result is achieved by modification of the substrate fabric with viscous polymer and the intact retention of SPCs. The sandwich structure formed by the adhesive polymer on the base fabric and the encapsulation of the film-forming material on the SPCs imparts good stability to the structural color fabric. It is worth noting that patterned photonic crystal coatings can be easily obtained on the fabrics made of different materials (cotton, linen, wool, and silk fabrics) by manipulating the shape of the viscous polymer. Additionally, a wide range of common materials, such as paper, wood, steel, and others, can be used as target substrates. This novel dyeing strategy not only offers new ideas for preparing patterned structural color fabrics but also further promotes the application of photonic crystal materials in textile printing or display.

Transformation of topological states in three-dimensional photonic crystal under magnetic field modulation

The realization and modulation of high-order topological states in three-dimensional (3D) photonic crystals (PCs) hold great significance for practical applications in optical communication, optical information processing, and optical computing. However, they have encountered technological challenges due to the difficulty in achieving a complete bandgap in 3D PCs. To address this issue, we introduce a design for a 3D PC based on the Su–Schrieffer–Heeger (SSH) model that exhibits distinctive topological surface states, topological hinge states, and topological corner states. Furthermore, these three types of topological states can be interconverted through the modulation of magnetic field because the topological states are closed and extremely sensitive to the structure, which are modulated by the magnetic field. This intriguing capability holds potential applications in the manipulation of optical flow, optical signal storage, and magnetic field sensors.

Second-harmonic flat-top beam shaping via a three-dimensional nonlinear photonic crystal.

We experimentally extend the nonlinear Gaussian to flat-top beam shaping from one to two dimensions through a three-dimensional nonlinear photonic crystal. Employing a near-infrared femtosecond laser, we induce a modification inside lithium niobate to achieve a second-order nonlinear optical coefficient modulation in three dimensions. The flat-topped truncation of wavefront has been adjusted in a mutual perpendicular coordinate separately. Among the generated flat-topped beams, the optimal flatness is 97.1%, and the nonlinear conversion efficiency is 10-2 at the peak power of 37 kW with the interaction length of 630 µm. By adding an extra dimension, our work simultaneously enables full-wavefront flat-top distribution and nonlinear frequency conversion.

Highly performance DMMP optical sensor based on zeolitic imidazolate frameworks three-dimensional photonic crystals

Due to protect soldiers and civilians in case of threats of chemical warfare agents (CWAs), there is an urgent need to develop a gas sensor with high selectivity, sensitivity, and excellent stability for detecting CWAs. Herein, we proposed a three-dimensional photonic crystals (3D PCs) gas sensor based on zeolitic imidazolate frameworks (ZIFs) for the detection of CWAs simulant, dimethyl methyl phosphonate (DMMP). ZIFs particles with different metal ion contents were induced to self-assemble into ZIF-8, Co/Zn ZIFs and ZIF-67 3D PCs sensors in a template-free method. The sensing application of ZIFs 3D PCs sensors for the detection of DMMP vapor was investigated. The ZIF-8 3D PCs sensor showed excellent sensing performance for DMMP, with a concentration sensitivity of 0.10 nm ppm−1 and a limit of detection of up to sub-ppm level (LOD = 0.99 ppm) at room temperature. Moreover, the ZIF-8 3D PCs sensor exhibited high stability and repeatability, and keeps remarkable sensing performance under heat treatment at 200 °C and long-term storage conditions for 30 days. Our results reveal that ZIF-8 3D PCs sensor is a promising candidate for the effective detection of DMMP vapor, opening up a new strategy for the use of ZIFs for chemical warfare agents monitoring in optical sensing.

Manipulation of random laser by the bandgap in three-dimensional SiO2 photonic crystals

Photonic crystals (PCs) are artificial structures with different dielectric constants that are arranged periodically in space and can control the propagation of electromagnetic waves of specific frequencies. The photonic bandgap can tune the photon state density, which is beneficial for the generation of random lasers (RLs). In this paper, a thin film of PMMA-doped DCJTB is spun-coated on a silicon dioxide (SiO2)PC to produce an RL. The PC is fabricated by a convenient dip-coating method with variable PBGs by changing the diameter of SiO2 nanospheres. By changing the position of the PBG gap, the RL emission peak can be effectively manipulated with an emission wavelength of up to 16 nm. By adding Au nanoparticles, the lasing performance is improved due to the surface plasmon resonance effect and strong photon scattering, where the emission intensity is increased by 191.9 %, and the threshold is decreased by 37.8 %. The imaging results show that the RL has low spatial coherence, which has a good application in speckle-free imaging. This study provides an effective method to produce a low threshold, high-quality RL with convenient manipulation of lasing properties, which opens the door for expanding its application in optoelectronic devices and speckle-free imaging.

Light concentration and electron transfer in plasmonic-photonic Ag,Au modified Mo-BiVO4 inverse opal photoelectrocatalysts.

Plasmonic photocatalysis based on metal-semiconductor heterojunctions is considered a key strategy to evade the inherent limitations of poor light harvesting and charge separation of semiconductor photocatalysts. It can be profitably combined with three-dimensional photonic crystals (PCs) that offer an ideal scaffold for loading plasmonic nanoparticles and a unique architecture to intensify photon capture. In this work, Mo-doped BiVO4 inverse opals were applied as visible light-responsive photonic hosts of Ag and/or Au plasmonic nanoparticles in order to exploit the synergy of plasmonic and photonic amplification effects with interfacial charge transfer for the photoelectrocatalytic degradation of recalcitrant pharmaceutical contaminants under visible light. Photoelectrochemical evaluation indicated a major contribution from hot spot-assisted local field enhancement, most pronounced for Ag/Mo-BiVO4 PCs due to the spectral overlap of the localized surface plasmon resonance with the electronic absorption and blue-edge slow photon region of Mo-BiVO4 PCs, in contrast to weak plasmonic sensitization effects for the Au-modified PCs. The diverse band alignment at the metal-semiconductor interfaces resulted in the enhanced photoelectrocatalytic degradation of tetracycline broad spectrum antibiotic by Ag/Mo-BiVO4 and the refractory ibuprofen drug by (Ag,Au)/Mo-BiVO4, attributed to the enhanced charge separation by electron transfer toward Ag nanoparticles. Combination of visible light activated semiconductor PCs and plasmonic nanoparticles with suitable band alignment and photonic band gap may provide a versatile approach for the rational design of efficient plasmonic-photonic photoeletrocatalysts.

Three-dimensional opal-like photonic crystals made of diamond shells by chemical vapor deposition

3D ordered hollow diamond spheres packed into opal structure have been synthesized by chemical vapor deposition using silicon inverse opal template which, in turn, was produced by molding of a bulk silica opal template. These 3D diamond opals demonstrate optical properties of photonic crystal with Bragg reflection peak in the visible range. Numerical modeling of the reflection spectra is performed using a scattering matrix calculation, and agrees well with the measured Bragg peak positions. The porous structure consisting of nanocrystalline diamond shells with thickness of the order of 10 nm composes the light-weight material with density of ≈0.50 g/cm3. The diamond opals showed bright photoluminescence at 738 nm wavelength due to silicon-vacancy centers formation in course of the growth process. The diamond opals can be a new promising platform for versatile applications, primarily in photonics, due to wide transparency window, high chemical resistance and mechanical strength inherent to diamond.

Studies on temperature-dependent bandgap and gap-to-midgap ratio in diamond lattice photonic crystal with biosensing applications

The present study examines the temperature dependence of the photonic bandgap, the corresponding wavelength and the gap-to-midgap ratio in a three-dimensional diamond lattice photonic crystal. The bandgap calculations establish that the structure shows a complete photonic bandgap centered around 1550 nm at 300 K. The thermo-optic effect, observed in silicon, is employed to compute the photonic bandgap, band-edge wavelengths and mid-bandgap wavelength at various temperatures in the range of 300 K–400 K. The gap-to-midgap ratio, for the proposed structure, is also evaluated at different temperatures. It is seen that the upper and lower band-edge wavelengths and the mid-bandgap wavelength show a linear temperature dependence. The sensitivity of the structure is observed to be 0.0518 nm/K, thus supporting temperature sensing applications. It is found that the gap-to-midgap ratio, for the proposed diamond lattice structure, shows linear variation with temperature. The effect of variation of the dielectric constant and the fill factor on the gap-to-midgap ratio for the diamond structure has also been analyzed. The proposed design has also been analyzed as a refractive index sensor with a sensitivity of 254.9 nm/RIU for sensing the different components of blood.

Real higher-order Weyl photonic crystal

Higher-order Weyl semimetals are a family of recently predicted topological phases simultaneously showcasing unconventional properties derived from Weyl points, such as chiral anomaly, and multidimensional topological phenomena originating from higher-order topology. The higher-order Weyl semimetal phases, with their higher-order topology arising from quantized dipole or quadrupole bulk polarizations, have been demonstrated in phononics and circuits. Here, we experimentally discover a class of higher-order Weyl semimetal phase in a three-dimensional photonic crystal (PhC), exhibiting the concurrence of the surface and hinge Fermi arcs from the nonzero Chern number and the nontrivial generalized real Chern number, respectively, coined a real higher-order Weyl PhC. Notably, the projected two-dimensional subsystem with kz = 0 is a real Chern insulator, belonging to the Stiefel-Whitney class with real Bloch wavefunctions, which is distinguished fundamentally from the Chern class with complex Bloch wavefunctions. Our work offers an ideal photonic platform for exploring potential applications and material properties associated with the higher-order Weyl points and the Stiefel-Whitney class of topological phases.

Type-II Weyl points and one-way interface transmission in a three-dimensional gyromagnetic photonic crystal

Type-II Weyl points and one-way interface transmission in a three-dimensional gyromagnetic photonic crystal

Degeneration of topological corner, hinge, and surface states in three-dimensional photonic crystals.

The third-order topological insulators based on three-dimensional (3D) photonic crystals (PCs) have hardly been achieved because the nontrivial bandgap in 3D PCs is difficult to form. In this Letter, we elaborately construct 3D Su-Schrieffer-Heeger lattice in which the periodic modulation of refractive index is uniform in three axis directions. The high-order topological PCs are characterized by the nontrivial bulk polarizations and the mirror eigenvalues. Such a structure can achieve topological 1-codimensional surface states, 2-codimensional hinge states, and 3-codimensional corner states. More importantly, it is found for the first time, to the best of our knowledge, that the topological states exhibit a degeneration behavior, i. e., the corner, and hinge state, or corner and surface states coexist at nearly the same frequency, but maintain their own mode properties. The multiple topological states in 3D PCs as well as the degeneration of topological states will open a new window for the study of topological photonics.

Pick and place process for uniform shrinking of 3D printed micro- and nano-architected materials

Two-photon polymerization lithography is promising for producing three-dimensional structures with user-defined micro- and nanoscale features. Additionally, shrinkage by thermolysis can readily shorten the lattice constant of three-dimensional photonic crystals and enhance their resolution and mechanical properties; however, this technique suffers from non-uniform shrinkage owing to substrate pinning during heating. Here, we develop a simple method using poly(vinyl alcohol)-assisted uniform shrinking of three-dimensional printed structures. Microscopic three-dimensional printed objects are picked and placed onto a receiving substrate, followed by heating to induce shrinkage. We show the successful uniform heat-shrinking of three-dimensional prints with various shapes and sizes, without sacrificial support structures, and observe that the surface properties of the receiving substrate are important factors for uniform shrinking. Moreover, we print a three-dimensional mascot model that is then uniformly shrunk, producing vivid colors from colorless woodpile photonic crystals. The proposed method has significant potential for application in mechanics, optics, and photonics.

Research and Application Progress of Inverse Opal Photonic Crystals in Photocatalysis

In order to solve the problem of low photocatalytic efficiency in photocatalytic products, researchers proposed a method to use inverse opal photonic crystal structure in photocatalytic materials. This is due to a large specific surface area and a variety of optical properties of the inverse opal photonic crystal, which are great advantages in photocatalytic performance. In this paper, the photocatalytic principle and preparation methods of three-dimensional inverse opal photonic crystals are introduced, including the preparation of basic inverse opal photonic crystals and the photocatalytic modification of inverse opal photonic crystals, and then the application progresses of inverse opal photonic crystal photocatalyst in sewage purification, production of clean energy and waste gas treatment are introduced.

A Brief Review on Nonlinear Photonic Crystals Induced by Direct Femtosecond Laser Writing

Direct femtosecond laser writing or inscription is a useful technique, and it has been employed to engineer various materials in many applications including nonlinear photonic crystals, which are of periodically patterned second-order nonlinearity to get and control the coherent light at new frequencies. By manipulation of second-order nonlinearity, either erased or poled, quasi-phase matching has been achieved in several crystals, especially three-dimensional nonlinear photonic crystals have been originally proposed and proved to be truly three-dimensional. Here we shortly review on the recent advances in the research field of nonlinear photonic crystals inscribed by femtosecond laser, as well as look into the future in this field.

Ultra-trace chlorinated gases optical sensor with moisture-resistant based on structural-customizable UiO-66 3D photonic crystals

Chlorinated gases seriously pollute the environment and threaten human health. Limitation of insufficient adsorption sites and interference of atmospheric humidity, designing an advanced sensing device with high adsorption and moisture resistance is still a challenge to detect chlorinated gases for air monitoring. Herein, a moisture-resistant optical sensor based UiO-66 three-dimensional (3D) photonic crystals is achieved. The optical sensor shows customizable structure and tunable optical properties, which are benefit to gas diffusion and signal transduction. The application of the optical sensor for 2.5 ppm carbon tetrachloride (CCl4), dichloromethane (CH2Cl2), chlorobenzene (C6H5Cl) and hydrochloric acid (HCl) detection was investigated in relative humidity (RH) 35%. The sensor exhibits excellent selectivity for HCl, which agree with the density functional theory (DFT) calculations for the adsorption energy. Especially, the sensor exhibits high stability and repeatability under RH 50%− 95%, and the sensing performance of the sensor for 2.5 ppm HCl has improved at RH up to 65%, limit of detection (LOD) can reach 10.9 ppb, ultra-fast response was 0.49 s. The improvements in sensing performance under RH are attributed to moisture-enhanced adsorption mechanism. This work provides a new insight for effective utilization of advanced materials and device to achieve ultra-trace chlorinated gas detection in humid atmosphere.

Generation of nonlinear Airy beams with switchable acceleration direction

Airy beams, which propagate along a curved trajectory, have been widely utilized in optical tweezers, biomedical analysis, and material processing. However, the dynamic regulation of nonlinear Airy beams is still challenging. Here, we demonstrate directionally switchable nonlinear Airy beams via three-dimensional (3D) nonlinear photonic crystals (NPCs) fabricated by the femtosecond laser erasing technique. The 3D NPCs contain several sequential arrays of spatially modulated nonlinearities with different spatial frequencies and cubic coefficients. By tuning the wavelength of the fundamental beam, the quasi-phase-matching condition can be switched to modulate the acceleration direction and wavelength of the generated nonlinear Airy beam. This offers a versatile platform for dynamic nonlinear Airy beam generation, paving the way for applications in optical trapping, optical communication, and biomedical imaging.

Responsive photonic hydrogel for colorimetric detection of formaldehyde

Formaldehyde (FA) can damage DNA, cause liver and kidney dysfunction, and ultimately lead to malignant tumors. Therefore, it is essential to develop a method that can conveniently detect FA with high detection sensitivity. Here, a responsive photonic hydrogel was prepared by embedding three-dimensional photonic crystal (PC) into amino-functionalized hydrogel to construct a colorimetric sensing film for FA. The amino groups on the polymer chains of the photonic hydrogel reacts with FA to increase the crosslinking density of the hydrogel, resulting in its volume shrinkage and a decrease in microsphere spacing of the PC. That causes the reflectance spectra blue-shift of more than 160 nm and color change from red to cyan for the optimized photonic hydrogel, achieving the sensitive, selective and colorimetric detection of FA. The constructed photonic hydrogel shows good accuracy and reliability for practical determination of FA in air and aquatic products, providing a new strategy for designing other target analytes responsive photonic hydrogels.

Direct ink writing of three-dimensional Al2O3/polydimethylsiloxane photonic crystal heterostructures for terahertz frequencies

The photonic crystal heterostructures with multi-bandgap could manipulate multiple optical signals simultaneously, and have important applications in various multi-channel optical or optoelectronic devices. However, due to the limitations of materials and structure complexity, photonic crystal heterostructures for terahertz frequencies are rarely reported. Here, we report a facile and efficient approach to fabricate terahertz photonic crystal heterostructures (TPCHs) via direct ink writing (DIW) 3D printing technology. Al2O3/polydimethylsiloxane (PDMS) composite ink suitable for DIW has been developed. Al2O3/PDMS TPCHs with different structural parameters have been fabricated by DIW 3D printing. The results of simulation and experiments demonstrate that these TPCHs exhibit some special optical properties, such as bandgap deepening and dual-bandgap, compared with the conventional three-dimensional terahertz photonic crystals (3D-TPCs). The optical properties of TPCHs could be accurately regulated by varying the lattice constant of their compositional 3D-TPCs. The DIW 3D printing technology offers a new opportunity to create TPCHs with tailored photonic behavior for novel terahertz functional devices.