Light Reflection Research Articles

Comparative Temporal Infrared Thermography of Arboricultural Materials for Sun‐Induced Trunk Injury Prevention in Broad‐Leaved Woody Plants

ABSTRACTUsing an infrared (IR) thermal camera, we evaluated the efficacy of six arboricultural materials for preventing sunscald and frost crack. The trunks of adult Yoshino cherry (Prunus × yedoensis) and Japanese zelkova (Zelkova serrata) were treated with (i–iii) three paint types (white water paint [P–W], white latex paint [P–L], and quicklime [P–Q]), (iv and v) two band wrap types [brown tree wrap (B–B) and white tree wrap (B–W)], and (vi) a wound paste: thiophanate‐methyl paste (TP) in the shape of a band 10 cm thick. Outdoor IR thermographs were captured four times a day at 3 h intervals (09:00 a.m., 12:00 p.m., 03:00 p.m. and 06:00 p.m.) over four consecutive days in late October 2019. Bark temperatures recorded for P–W, P–L, P–Q and B–W treatments were consistently lower than those for untreated trunks. The mean temperature difference between B–W and untreated bark (up to 4.57°C) remained pronounced between 09:00 a.m. and 06:00 p.m. for both tree species each day. Conversely, no significant differences in bark temperatures were observed under B–B and TP treatments compared with untreated bark (p = 0.01). Elevated bark temperature was observed on the south side compared with the other three cardinal directions; however, temperatures were similar in all directions at 06:00 p.m. These findings suggest that white tree wrapping may provide a viable approach to prevent sun‐induced trunk injuries, leveraging the light reflectivity of the white colour and thermal insulation properties of the wrapping material.

Synergetic integration of photothermal and self-cleaning features in a composite phase change material based on layered double hydroxides and polypyrrole

Composite phase change materials (PCMs) with photothermal functionality play a crucial role in efficiently storing and utilizing solar energy. However, the challenge of effectively removing of contaminants on photothermal conversion coatings has long puzzled researchers. In this study, we propose a novel approach to enhancing both photothermal conversion performance and self-cleaning properties of wood-based composite phase change materials, ultimately facilitating the sustainable and effective utilization of solar energy. The method utilized metal-organic frameworks (MOFs) as a precursor to form rough layered double hydroxides (LDH) on the wood surface through hydrolysis-induced exchange. Subsequently, polypyrrole (PPy) was deposited through vapor phase onto the LDH, and paraffin wax (PW) is utilized as the phase change material to prepare a novel composite phase change material. This modified wood structure facilitates leak-proof PW encapsulation and effective heat storage (167.6 J/g). PPy acts as a proficient photothermal converter and improves the composite material's heat transfer efficiency by establishing thermal conduction pathways, resulting in an 87.4 % enhancement in thermal conductivity compared to pure PW. The rough surface of LDH promotes multiple light reflections and scattering within the material, leading to increased light absorption by the PPy coating and achieving a photothermal conversion efficiency of up to 96.4 %. Furthermore, the high roughness of the LDH layer combined with the low surface energy of PW imparts superhydrophobic self-cleaning properties to the material, ensuring sustained effectiveness of the photothermal conversion coating over time. This research presents a viable approach for maintaining the cleanliness and efficiency of solar energy systems.

Core-Shell Composite Nanofibers with High Temperature Resistance, Hydrophobicity and Breathability for Efficient Daytime Passive Radiative Cooling.

Radiative cooling technology, which is renowned for its ability to dissipate heat without energy consumption, has garnered immense interest. However, achieving high performance, multifunctionality, and smart integration while addressing challenges such as film thickness and enhancing anisotropic light reflection remains challenging. In this study, a core-shell composite nanofiber, PVDF@PEI, is introduced and designed primarily from a symmetry-breaking perspective to develop highly efficient radiative cooling materials. Using a combination of solvent-induced phase separation (EIPS) inverse spinning and (aggregation) self-assembly methods (EISA or EIAA) and coaxial electrostatic spinning (ES), superconformal surface anisotropic porous nanofiber membranes are fabricated. These membranes exhibit exceptional thermal stability (up to 210°C), high hydrophobicity (contact angle of 126°), robust UV protection (exceeding 99%), a fluorescence multiplication effect (with a 0.6% increase in fluorescence quantum efficiency), and good breathability. These properties enable the material to excel in a wide range of application scenarios. Moreover, this material achieved a remarkable daytime cooling temperature of 8°C. The development of this fiber membrane offers significant advancements in the field of wearables and the multifunctionality of materials, paving new paths for future research and innovation.

USING 5E INSTRUCTIONAL MODEL WITH ICT SUPPORT IN TEACHING LOWER SECONDARY STUDENTS ON THE TOPIC OF LIGHT REFLECTION

The educational process has become more accustomed to active classroom engagement. Physics teaching should focus more on young pupils’ investigative journey. This research investigates the effect of the ICT-based 5Es instructional model on the conceptual understanding and science process skills of grade 6 pupils on light reflection. The 5E Model stands for Engage, Explore, Explain, Elaborate, and Evaluate. The study used a mixed-method design involving 24 students participating in a 5E-based intervention. The pre- and post-test results showed a significant improvement in conceptual knowledge and science process skills. Statistical analysis using paired t-tests and Cohen's d found that the 5E Model has significantly improved students' conceptual understanding of the topic and their science process skills. The study also used a phenomenological analysis and identified three critical themes that contributed to the success of the intervention. These themes were high interest and excitement in using laboratory materials, collaboration among students in exploring light reflection, and teacher scaffolding and facilitation to help students overcome challenges. The 5Es Model, which involves engaging, examining, explaining, elaborating, and evaluating stages, was highly influential in keeping students interested and enthusiastic throughout the learning process. The study confirms that the 5Es instructional model positively impacts students’ science process skills and conceptual understanding. Using both quantitative and qualitative analyses provides a thorough understanding of the intervention’s effectiveness and offers recommendations for improving the implementation of the 5Es Model in science education. This study recommended providing professional development opportunities for teachers to enhance their skills in implementing the 5Es instructional model. Regular workshops, collaborative sessions, and opportunities for knowledge exchange can equip teachers with up-to-date teaching strategies and insights.

On the impact of hollow silica powder on the performance of aerogel glazing systems in buildings: Results from laboratory and simulation analyses

Aerogel-based glazing systems are an effective solution to reduce space heating energy use in buildings, even if overheating risks in temperate climates exist due to the high solar transparency of the systems. This study analyzes the potential of an innovative solution, based on a mixture of granular aerogel and hollow silica powder, in small concentrations, to increase the reflectance of the aerogel layer and reduce solar transmission. A set of glazing samples, different in aerogel layer and powder concentration, were produced and test in laboratory to determine the relevant solar and thermal properties. It was found that at 7.5 % powder concentration the solar and light transmittance were reduced up 0.48 and 0.45 in a 0–1 scale, respectively. Analogously, the solar and light reflectance increased up 0.49 and 0.46, respectively. The thermal resistance of the system increased up to 0.18 m2K/W, peaking at 1.88 m2K/W for the 34 mm aerogel layer sample. The thermo-physical properties were used as input to simulate an office building in different climatic conditions; it was found that the proposed technology ensured total energy savings for 4 % powder concentration and higher; cooling energy savings were up to 21 % and total energy savings up to 21 %.

Deconstructing 3D growth rates from transmission microscopy images of facetted crystals as captured in situ within supersaturated aqueous solutions.

Here, a morphologically based approach is used for the in situ characterization of 3D growth rates of facetted crystals from the solution phase. Crystal images of single crystals of the β-form of l-glutamic acid are captured in situ during their growth at a relative supersaturation of 1.05 using transmission optical microscopy. The crystal growth rates estimated for both the {101} capping and {021} prismatic faces through image processing are consistent with those determined using reflection light mode [Jiang, Ma, Hazlehurst, Ilett, Jackson, Hogg & Roberts (2024 ▸). Cryst. Growth Des. 24, 3277-3288]. The growth rate in the {010} face is, for the first time, estimated from the shadow widths of the {021} prismatic faces and found to be typically about half that of the {021} prismatic faces. Analysis of the 3D shape during growth reveals that the initial needle-like crystal morphology develops during the growth process to become more tabular, associated with the Zingg factor evolving from 2.9 to 1.7 (>1). The change in relative solution supersaturation during the growth process is estimated from calculations of the crystal volume, offering an alternative approach to determine this dynamically from visual observations.

Plasmonic Nanotrenches with 1 nm Nanogaps for Surface-Enhanced Raman Scattering-Based Screening of His-Tagged Proteins.

This study represents a highly sensitive and selective approach to protein screening using surface-enhanced Raman scattering (SERS) facilitated by octahedral Au nanotrenches (OANTs). OANTs are a novel class of nanoparticles characterized by narrow, trench-like excavations indented into the eight facets of a Au octahedron. This unique configuration maximizes electromagnetic near-field focusing as the gap distance decreases to ∼1 nm. Owing to geometrical characteristics of the OANTs, near-field focusing can be maximized through the confinement and reflectance of light trapped within the trenches. We used Ni ions and molecular linkers to confer selective binding affinity for His-tagged proteins on the surfaces of the OANTs for SERS-based protein screening. Remarkably, SERS-based protein screening with the surface-modified OANTs yielded outstanding screening capabilities: 100% sensitivity and 100% selectivity in distinguishing His-tagged human serum albumin (HSA) from native HSA. This highlights the significantly enhanced protein screening capabilities achieved through the synergistic combination of SERS and the OANTs.

Nanofiber aerogel with layered array with structure coupled photothermal/magnetothermal effect for continuous seawater desalination

The solar evaporation is susceptible to intermittent solar irradiation as well as salt crystallization deposition on the surface severely limits the evaporation efficiency. In this work, subject to inspiration of the transpiration, groove array structure and antifouling performance of banana leaves, a multifunctional photothermal/ magnetothermal coupled three-dimensional(3D) aerogel evaporator with layer-by-layer array structure was prepared by blow-spun technology which can achieve mass produced. The unique super hydrophilic vertical array structure has multi-scale high-efficiency water transport channels and the SnSe-Fe3O4 evaporation layer realizes super hydrophobic self-cleaning and excellent photothermal and magnetothermal conversion performance, which can achieve all-weather seawater desalination. The vertical array structures facilitate the reflection and refraction of light and promote the seawater convection and salt crystals absorption coupling. It could improve the photothermal conversion efficiency and salt resistance of the evaporator. Which resulted in an evaporation rate of 2.53 kg m−2h−1 under 1 sun, with solar energy conversion efficiency of 105 % and the evaporation rate is about 4.54 kg m−2h−1 at a magnetic field. Furthermore, it could purify organic pollutants in industrial wastewater and use waste heat to generate electricity. This evaporator provides a new economical and environmentally friendly solution for seawater desalination and sewage treatment.

RSE-YOLOv8: An Algorithm for Underwater Biological Target Detection.

Underwater target detection is of great significance in underwater ecological assessment and resource development. To better protect the environment and optimize the development of underwater resources, we propose a new underwater target detection model with several innovations based on the YOLOv8 framework. Firstly, the SAConv convolutional operation is introduced to redesign C2f, the core module of YOLOv8, to enhance the network's feature extraction capability for targets of different scales. Secondly, we propose the RFESEConv convolution module instead of the conventional convolution operation in neural networks to cope with the degradation of image channel information in underwater images caused by light refraction and reflection. Finally, we propose an ESPPF module to further enhance the model's multi-scale feature extraction efficiency. Simultaneously, the overall parameters of the model are reduced. Compared to the baseline model, the proposed one demonstrates superior advantages when deployed on underwater devices with limited computational resources. The experimental results show that we have achieved significant detection accuracy on the underwater dataset, with an mAP@50 of 78% and an mAP@50:95 of 43.4%. Both indicators are 2.1% higher compared to the baseline models. Additionally, the proposed model demonstrates superior performance on other datasets, showcasing its strong generalization capability and robustness. This research provides new ideas and methods for underwater target detection and holds important application value.

Wide‐Range Wavelength Light Scattering from Black Silicon Layers: Profits for Perovskite/Si Tandem Solar Cells

This study investigates the optical properties (light reflectance, absorptance, transmittance, and scattering) of black silicon (b‐Si) layers formed using reactive ion etching method. The corresponding spectra are determined across the visible, near‐infrared, and near‐ultraviolet wavelength ranges (250–1400 nm). It is demonstrated that b‐Si layers reduce the reflectance, and increase the absorptance and light scattering due to the disordered distribution of the nanoneedles. Increasing the etching duration strengthens this trend. It is shown that b‐Si layers etched for 10 min can be considered perfect light scatterers upon reflection at wavelengths less than 700 nm. Based on the obtained results, the possible profits of light scattering from the b‐Si interlayer for perovskite/Si tandem solar cells are analyzed. It is substantiated that the b‐Si interlayer can increase the useful absorptance not only within the bottom Si solar subcell but also in the top perovskite solar subcell. The prospects for future research directions and challenges are also provided.

Development and Optimization of Micro‐Nanotopographical Platforms for Surface Enhanced Raman Scattering Biomolecular Detection

AbstractTopologically designed micro‐ and nanostructured surface‐enhanced Raman scattering (SERS) substrates propel the advancements of innovative applications, including environmental and forensic point‐of‐care miniaturised devices via enhancing the localised electric fields for accurate analyte sensing. Herein, a method for designing, optimising and fabricating fine‐tuneable concentric hexagonal, triangular and rectangular SERS‐active micronano‐substrates is developed, with each unit yielding significant enhancement. Numerical simulations of the 3D near‐field electric field guided the optimal design process. While the coaxial SERS substrates consistently outperformed their solid counterparts, the hexagonal micro‐nano topologies exhibited ×21 higher signal than coaxial square arrays and a 12‐15‐fold increase over the triangle structures. Alternation of the topological designs from square to triangle lattice yielded more uniform plasmonic modes propagating along the 60°‐directions with various resonance modes playing key roles in light reflectance. This enables the engineering of platforms with tailor‐enhanced signals by changing the arrangement of micro‐nano patterned coaxial arrays. The fabricated SERS substrates are validated by detecting traumatic brain injury biomarkers, effectively yielding the characteristic fingerprint spectra of each neuro‐molecule. The straightforward development of sub‐micrometre tuneable SERS‐active architectures enables anelegant route for high‐throughput biochemical sensing, laying a platform for amplified bimolecular detection of disease biomarkers and integration in bioanalytical systems.

Three-dimensional object reconstruction based on spin–orbit interaction of light

Three-dimensional (3D) reconstruction has received extensive attention in recent years and is of great significance to various application fields. We propose a simple method of 3D object reconstruction based on spin–orbit interactions occurring from light reflection at the air–glass interface. By rotating the object, edge images of the object in various orientations are obtained; we overlap these edge images to ultimately reconstruct the 3D object. This 3D image detection based on spin–orbit interaction of light provides a low energy consumption, low cost, and more algorithmic method compared to traditional 3D image processing. This can be used in fields such as medicine, autonomous vehicles, planetary observation, and other areas.

High-efficiency GaAs TFSC based on Ti plasma enhancement

This study proposed a performance enhancement scheme for GaAs thin-film solar cell (TFSC) based on Ti plasma enhancement. It aims to enhance the light absorption ability of the cell by using surface plasmon excitations of metal nanoparticles, and to predict and optimize the performance of the TFSC using the FDTD method. By introducing Ti nanosphere and pyramid structures on the upper and lower surfaces of the cell, the reflection and transmission losses of light are effectively reduced. This increases the interaction between the cell materials and light, and significantly improves the cell's ability to absorb light. It is shown that Ti nanosphere and pyramid structures can localize the electric field near the metal surface, which greatly enhances the absorption of light on the upper and lower surfaces of the cell. In the wavelength range of 380–1200 nm, the absorption of all bands reaches more than 93 %, with an average absorption rate as high as 97.60 %, and is close to perfect absorption in the wavelength range of 700–900 nm. Meanwhile, the photoelectric conversion efficiency (PCE) of the cell reaches 32.72 %, which significantly improves the overall performance of the cell and provides a compelling design solution for the innovation and development of GaAs TFSC technology.

Enhanced electro-optical properties of polymer dispersed liquid crystals doped with functional nanofibers for applications of efficient smart windows and advanced anti-counterfeiting

The development of polymer-dispersed liquid crystal (PDLC) capable of infrared smart tuning and displaying distinct information under ultraviolet, visible, and infrared light presents significant challenges. These challenges include the tuning of electro-optical properties and IR reflectivity, the preparation of complex patterns, and the display of different display states under various stimuli. In this work, nanofibers doped with alumina-zinc oxide nanoparticles (AZO NPs) and loaded with cesium tungstate nanoparticles (Cs0.33WO3 NPs) into PDLC not only enhanced their electro-optical properties but also added infrared shielding. Temperature regulation tests demonstrate that PDLC films can intelligently modulate infrared light reflection, offering superior shading and temperature regulation capabilities. PDLC smart windows integrated with nanofibers achieve a temperature coordination function, maintaining a temperature differential of 12.1 °C compared to standard PDLC. This significant enhancement underscores their potential for applications in thermally regulated smart windows. In addition, a full-wavelength anti-counterfeiting mode for PDLC was developed using a screen-printing strategy to display different information under various wavelengths of light. Noteworthily, the anti-counterfeiting system exhibits a bright fluorescent pattern under UV light, a scattering pattern under visible light, and an infrared-modulated pattern when viewed with an infrared detector. Furthermore, an advanced dynamic anti-counterfeiting mode with time response was created using nanofibers loaded with different concentrations of Cs0.33WO3 NPs. This advanced anti-counterfeiting material can be used as multimodal and dynamic anti-counterfeiting label, which greatly facilitates the development of novel anti-counterfeiting and optical sensing materials.

Sustainable building envelopes: Evaluating the thermal performance of thatched roofs fabricated using coconut leaves

Excessive heat gain in residential buildings during sunny days, especially in tropical regions, leads to increased reliance on active energy cooling systems, contributing to higher carbon emissions and energy costs. Traditional roofing materials, such as terracotta tiles are often insufficient in mitigating indoor temperature rise, necessitating the exploration of alternative, sustainable solutions. This study investigates the thermal performance of naturally available coconut leaves used as thatch roofing, comparing it with conventional terracotta tiles, to determine their effectiveness in controlling interior temperatures and reducing heat gain in buildings. To mitigate such a problem, the Near Infra-Red (NIR) light reflectivity of dried plant leaves derived from deciduous and coniferous trees was measured. The structural hierarchy of the leaves was confirmed through Field Emission Scanning Electron Microscope (FESEM), Fourier Transform Infrared Spectroscope (FTIR) and X-ray Diffraction (XRD) studies. FTIR spectra reveal characteristic vibrations of ester, cellulosic components, etc., and XRD confirms the amorphous status of cellulosic materials present in the plant biomass. To study the use of thatched roofs made using coconut leaves as a roofing element, two test huts were fabricated - one was covered using terracotta roof tiles and the other was covered using coconut leaves thatches. The thermal performances of two roofing materials were recorded on a sunny day and the results were compared. The temperature data noticed reveal the fact that the maximum average surface temperature of the terracotta roof model was 59.53 °C, while the rooftop covered with coconut thatches exhibits a temperature of 54.26 °C which is 8.8% less than the hut covered with terracotta tiles. The interior temperature recorded in the coconut thatch was 33.36 °C, which was 1.15 °C lower (34.51 °C) than the terracotta tiles-covered test hut, confirming the better thermal comfortability of thatched roof model than a terracotta roof model.

Enhanced SERS performance of cavity-hosting silver dendrites grown over TiO2 nanotubes

Silver nanostructures, utilized as SERS substrates, consistently exhibit exceptional performance in detecting organic compounds through Raman spectroscopy, primarily due to the electromagnetic enhancement mechanism. This study explores an advanced SERS substrate composed of cavities formed by silver dendrites (Ag-Ds) on TiO2 nanotubes (TiO2-NT), demonstrating exceptional performance in detecting organic compounds through Raman spectroscopy. TiO2-NT acts as a template, guiding the nucleation and growth of Ag-D to create the cavity structures. The deposition time of silver significantly influences substrate performance in detecting Rhodamine 6G (R6G) and Ibuprofen (IB). It has been observed that an extended deposition time diminishes the enhancement factor. In contrast, a shorter deposition time yields notable enhancement due to the combined effects of electromagnetic and chemical enhancement mechanisms. An optimum deposition time limits dendrite growth, forming cavities where the electric field couples with multiple light reflections, further amplifying the SERS enhancement. The cavity-hosted Ag-D/TiO2-NT substrate achieves an impressive analytic SERS enhancement factor of up to 2 × 109, enabling the detection of R6G and IB at a low detection limit of 10-12 M.

Synthesis of high-value porous carbon from waste plastics and structure regulation promote solar interface water evaporation

Water scarcity and waste plastics elimination are long-term problems facing sustainable development, and solar interface evaporation to produce clean water is regarded as a promising water treatment technology. Herein, we report on low-cost waste plastic bottles synthetic carbon-based photothermal materials. By KOH activation and perforation, the surface crack structure of porous carbon is formed to facilitate multi-stage reflection of solar light, and significantly improve the solar light absorbance and photothermal conversion ability. Three-dimensional solar evaporators with low thermal conductivity and super hydrophilic wood sponge are fabricated, and the rectangular hole is designed to regulate water movement and prevent heat dissipation. When exposed to 1 sun illumination (1 kW/m2), an evaporation rate of 1.59 kg·m-2·h-1 is achieved, along with an energy conversion efficiency of 88.49 %. In addition, different micro-surface rough structures are constructed to boost the solar light absorption, thereby enhancing the photothermal conversion ability, among which the micro-cone structure increased the evaporation rate to 1.93 kg·m−2·h−1, demonstrating excellent stability over 15 cycles. In the simulated sewage purification process, the removal rate of pollutants is 99.9 %, and the evaporator without obvious salt accumulation in the seawater for 24 h, showing good salt resistance and self-cleaning ability. This research has important reference value for high-value preparation of carbon-based photothermal materials from waste plastics, extraction of clean water and environmental sustainable protection.

The genetic basis of the kākāpō structural color polymorphism suggests balancing selection by an extinct apex predator.

The information contained in population genomic data can tell us much about the past ecology and evolution of species. We leveraged detailed phenotypic and genomic data of nearly all living kākāpō to understand the evolution of its feather color polymorphism. The kākāpō is an endangered and culturally significant parrot endemic to Aotearoa New Zealand, and the green and olive feather colorations are present at similar frequencies in the population. The presence of such a neatly balanced color polymorphism is remarkable because the entire population currently numbers less than 250 birds, which means it has been exposed to severe genetic drift. We dissected the color phenotype, demonstrating that the two colors differ in their light reflectance patterns due to differential feather structure. We used quantitative genomics methods to identify two genetic variants whose epistatic interaction can fully explain the species' color phenotype. Our genomic forward simulations show that balancing selection might have been pivotal to establish the polymorphism in the ancestrally large population, and to maintain it during population declines that involved a severe bottleneck. We hypothesize that an extinct apex predator was the likely agent of balancing selection, making the color polymorphism in the kākāpō a "ghost of selection past."

Optical Methods for Optimizing Fluorescence Imaging Field of View and Image Quality in Surgical Guidance Procedures.

Cancer surgery is aimed at complete tumor resection and accurate lymph node detection. However, numerous blood vessels are distributed within the tumor, and the colors of the tumor, blood vessels, and lymph nodes are similar, making observations with the naked eye difficult. Therefore, tumors, blood vessels, and lymph nodes can be monitored via color classification using an operating microscope to induce fluorescence emission. However, as the beam width of the LED required to induce fluorescence emission is narrow and the power loss of the beam is significant at a certain working distance, there are limitations to inducing fluorescence emission, and light reflection occurs in the observation image, obstructing the view of the observation area. Therefore, the removal of reflected light is essential to avoid missing the diagnosis of the lesion under observation. This paper proposes the use of a beam mirror and polarizing filter to increase the beam width and beam intensity. The refraction and reflection effects of the beam were utilized using the beam mirror, and the rotation angle of the polarizing filter was adjusted to remove light reflection. Consequently, the minimum beam power using the beam mirror was 10.9 mW, the beam width was doubled to 40.2°, and more than 98% of light reflection was removed at 90° and 270°. With light reflection effectively eliminated, clear observation of lesions is possible. This method is expected to be used effectively in surgical, procedural, and diagnostic departments.

Anomalous reflection for highly efficient subwavelength light concentration and extraction with photonic funnels

Abstract Photonic funnels, microscale conical waveguides that have been recently realized in the mid-IR spectral range with the help of an all-semiconductor designer metal material platform, are promising devices for efficient coupling of light between the nanoscales and macroscales. Previous analyses of photonic funnels have focused on structures with highly conductive claddings. Here, we analyze the performance of funnels with and without cladding, as a function of material properties, operating wavelength, and geometry. We demonstrate that bare (cladding-free) funnels enable orders-of-magnitude higher enhancement of local intensity than their clad counterparts, with virtually no loss of confinement, and relate this phenomenon to anomalous reflection of light at the anisotropic material–air interface. Intensity enhancement of the order of 25, with confinement of light to wavelength/20 scale, is demonstrated. Efficient extraction of light from nanoscale areas is predicted.