For the analysis of ZnO luminescence, a set of rate equations (SRE) is proposed. It contains a set of parameters that characterize processes participating in luminescence: zone–zone excitation, excitons formation and recombination, formation and disappearance of photons, surface plasmons (SP), and phonons. It is shown that experimental ZnO microstructure radiation intensity dependence on photoexcitation levels can be approximated by using SRE. This approach was applied for the analysis of ZnO microfilm radiation with different thicknesses of Ag island film covering. It was revealed that the increase of cover thickness leads to an increase of losses and a decrease of the probability of photon-to-SP conversion. In order to take into account visible emission, rate equations for level populations in the bandgap and for corresponding photons and SPs were added to the SRE. By using such an SRE, it is demonstrated that the form of visible luminescence intensity dependence on excitation level (P) like P^1/3, as obtained elsewhere, is possible only if donor–acceptor pairs exist. The proposed approach was also applied for consideration of experimental results obtained in several papers taking into account the interpretation of these results based on assumptions about the transfer of electrons from the defect level in the ZnO bandgap to metal and then to the conduction band.

A silicon p-channel metal oxide semiconductor field-effect transistor (Si-PMOSFET) that is fully compatible with the standard complementary metal oxide semiconductor process is investigated based on the phenomenon of optical radiation observed in the reverse-biased p–n junction in the Si-PMOSFET device. The device can be used either as a two-terminal silicon diode light-emitting device (Si-diode LED) or as a three-terminal silicon gate-controlled diode light-emitting device (Si gate-controlled diode LED). It is seen that the three-terminal operating mode could provide much higher power transfer efficiency than the two-terminal operating mode. A new solution based on the concept of a theoretical quantum efficiency model combined with calculated results is proposed for interpreting the evidence of light intensity reduction at high operating voltages. The Si-LED that can be easily integrated into CMOS fabrication process is an important step toward optical interconnects.

Deep subwavelength plasmonic graphene nanoribbon waveguides for telecommunication frequencies are proposed. The mode properties of graphene nanoribbon waveguides with varied chemical potential are numerically investigated in terms of the effective indices and the propagation length of the plasmonic modes. A refractive index as high as 4980 is obtained on the plasmonic mode along the nanoribbon waveguide with a width of 3 nm at a frequency of 190 THz, and the normalized mode area on the scale of 10⁻⁸(1/λ₀)². An embedded graphene nanoribbon waveguide was also proposed and it is that the optical characteristic can be tuned by adjusting the chemical potential of graphene. The proposed structure can be a fundamental component of the future integrated plasmonic circuit system.

The transient nonlinear Schrodinger equation in which the frequency is a function of time is established to describe the fast-varying field in the process of supercontinuum generation. It is solved with two methods and validated by comparing its simulation results with those of reported experiments. Based on the simulations of this extended equation, it is also demonstrated that the second-order differential of the field to longitude (z) can be ignored in the supercontinuum generation, and the additive item caused by the relationship between frequency and time will induce a homogeneous frequency shift.

A hybrid surface plasmon waveguide (HSPWG) with a convex rib added on the metal surface is further investigated and analyzed theoretically. The high mode confinement and long propagation distance can be realized simultaneously by optimizing the waveguide geometry. Our designed structures can provide mode area and propagation distance achieving close to λ²/512 and 2200  μm respectively, which are better than the performance of the traditional HSPWG. Our structures are excellent, promising candidates for improving plasmonic devices in the fields of ultrafast modulators and low-threshold nanolaser.

A two-dimensional photonic crystal based on a lattice of silicon rods in air with a photonic bandgap in the visible and near-ultraviolet spectra is proposed by removing some of the silicon rods or resizing their radii to create a monotonically varying tapered line defect, thereby pertaining to a case of structure-based nonlinearity and making it possible to operate with low input powers. By properly manipulating the length of the line defect, pulse compression and consequent adiabatic amplification are seen, along with bunching/antibunching of pulses. For certain modes of operation, field confinement is observed, and this leads to the formation of discrete pulses, or light bullets. Such a structure can be used as a multifunctional device, with some of the functionalities being optical nonpumped amplification, frequency upconversion, memory writing, matched termination, and slow wave guiding, which form the major conclusions of the work.

We propose a temperature sensor design based on the two-dimensional (2-D) photonic crystals (PhCs) microcavity coupled to two waveguides. We consider a Si 2-D PhC, and the refractive index (RI) of distilled water in holes has been taken as temperature dependent. The resonant wavelength will shift when temperature variation induces change in the RIs of the distilled water. The temperature variation causes the shifting of defect modes. The transmission characteristics of light in the sensor under different RIs that correspond to the change in temperatures are simulated by using the finite-difference time-domain method. A sensitivity of 84  pm/°C was achieved with the structure proposed. This property can be exploited in the design of a temperature sensor.

The structural designs of nonmagnetic chiral nihility-based optical fibers of elliptical and circular cross-sections, embedded with conducting sheath helix structure at the core–cladding interface, are investigated. Emphasis is given to the power confinement patterns while considering the hybrid EH₀₁, EH₁₁, and EH₂₁ modes in the fiber and their comparative features. Variations in fiber dimensions are considered, and the corresponding effects on the power confinements under different orientations of sheath helix structure are reported. It has been found that the chiral nihility-based fiber structure results in the enhancement of the confined power, particularly in the case of an elliptic fiber. Apart from these, keeping in mind the possible lossy nature of chiral nihility mediums, the dispersive characteristic of material is also considered for both kinds of cross-sectional geometry, and the results are compared with situations when the mediums are lossless. The results essentially indicate less confinement of power in the case of lossy mediums.

Mode splitting (MS) in whispering gallery microresonators provides excellent noise suppression in sensing signal compared to mode shifting. Here, we theoretically studied the ability of hollow bottle microresonators for detection of a single nanoparticle in air and water medium by MS phenomenon. To find out the optimum condition of sensor for nanoparticle (NP) detection, the effects of bottle geometry parameters, mode orders, and mode polarization state was investigated. The first radial transverse electric mode demonstrated the best sensitivity when the resonator radius and wall thickness were 10 and 0.3  μm, respectively. However, transverse magnetic modes manifested slightly better detection limit. In the air core hollow microbottle resonator (HMBR), the best detection limit of 3.1 nm radius for polystyrene NPs was achieved at an optimum condition of 30-μm resonator radius and 0.8-μm wall thickness. While MS could not be resolved in deionized water filled HMBRs for all of the investigated conditions at 1550 nm, changing the wavelength to 780 nm provided a detection limit of 15.1 nm in water. Furthermore, it is found that the sensitivity of HMBR is increased by at least two times in comparison with a microtoroid sensor. HMBRs are optofluidic platforms, so employing them could drastically enhance the applicability of microresonator-based systems for label-free NP detection.

Core–shell indium gallium nitride (InGaN)/gallium nitride (GaN) structures are attractive as light emitters due to the large nonpolar surface of rod-like cores with their longitudinal axis aligned along the c-direction. These facets do not suffer from the quantum-confined Stark effect that limits the thickness of quantum wells and efficiency in conventional light-emitting devices. Understanding InGaN growth on these submicron three-dimensional structures is important to optimize optoelectronic device performance. In this work, the influence of reactor parameters was determined and compared. GaN nanorods (NRs) with both {11-20}a-plane and {10-10}m-plane nonpolar facets were prepared to investigate the impact of metalorganic vapor phase epitaxy reactor parameters on the characteristics of a thick (38 to 85 nm) overgrown InGaN shell. The morphology and optical emission properties of the InGaN layers were investigated by scanning electron microscopy, transmission electron microscopy, and cathodoluminescence hyperspectral imaging. The study reveals that reactor pressure has an important impact on the InN mole fraction on the {10-10}m-plane facets, even at a reduced growth rate. The sample grown at 750°C and 100 mbar had an InN mole fraction of 25% on the {10-10} facets of the NRs.

At first, bulk-heterojunction polymer solar cells (PSCs) with conventional configuration: ITO/PEDOT:PSS/P3HT:C60/Al, containing different blend ratios of poly(3-hexylthiophene):fullerene, (P3HT):C60 as active layer have been fabricated. The effect of replacement of poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) by the prepared polyaniline-fumed silica (PANI-SiO₂) nanocomposites as the hole-collecting layer (HCL) on the performance of the fabricated PSC with the optimized blending ratio of P3HT:C60 was examined in detail. According to the obtained results, it was found that the fabricated PSC with PANI-SiO₂ nanocomposite containing 10% SiO₂ (PANI-10% SiO₂) as the HCL and P3HT:C60 with the optimized blending ratio (P3HT:33% C60) as active layer exhibited best performance with a fill factor (FF) of 0.35, compared to the PSC containing conventional PEDOT:PSS HCL with an FF of 0.32. Our demonstration suggests that PANI-SiO₂ nanocomposites could be promising HCL replacing PEDOT:PSS in PSCs as well as other organic electronic devices.

This work investigates the relationship between the Q factor of a silica microsphere coated with nonlinear optical molecules and the surface density of the nonlinear molecules. Two types of nonlinear molecules are studied: poly{1-[p-(3′-carboxy-4′-hydroxyphenylazo) benzenesulfonamido]-1,2-ethandiyl} (PCBS), and Procion Brown MX-GRN (PB). In our experiments, we coat silica microspheres with ionic self-assembled multilayer films with different thicknesses as well as with different PCBS/PB chromophores densities. The Q factors of the coated microspheres are measured to be within the range of 10⁶ to 10⁷, which can be attributed to the optical absorption of the coated chromophores. This work can be used to experimentally determine the effective density of chromophores assembled on the silica microsphere. It may also find applications in chemical/biological sensing.

We investigate the interference of two photons in an optical gating Michelson interferometer. The phenomenon is studied using two different representations of photons: the space-time domain and a step-by-step two-photon state evolution. Both representations lead to identical results. The evolution analysis describes the result by the interference of four two-photon traveling states, whereas the space-time domain analysis reveals that the classical interference of the high-intensity light source is identical to two-photon interference in the quantum regime, except for a multiplicative factor of (ⁿ₂) , where n is the number of photons.

Converting blackbody thermal radiation to electricity via thermophotovoltaics (TPV) is inherently inefficient. Photon recycling using cold-side filters offers potentially improved performance but requires extremely close spacing between the thermal emitter and the receiver, namely a high view factor. Here, we propose an alternative approach for thermal energy conversion, the use of an integrated photonic crystal selective emitter (IPSE), which combines two-dimensional photonic crystal selective emitters and filters into a single device. Finite difference time domain and current transport simulations show that IPSEs can significantly suppress sub-bandgap photons. This increases heat-to-electricity conversion for photonic crystal based emitters from 35.2 up to 41.8% at 1573 K for a GaSb photovoltaic (PV) diode with matched bandgaps of 0.7 eV. The physical basis of this enhancement is a shift from a perturbative to a nonperturbative regime, which maximized photon recycling. Furthermore, combining IPSEs with nonconductive optical waveguides eliminates a key difficulty associated with TPV: the need for precise alignment between the hot selective emitter and cool PV diode. The physical effects of both the IPSE and waveguide can be quantified in terms of an extension of the concept of an effective view factor.

An analytical model of optical gain is developed for three types of surface plasmon nano-oscillators: (i) a metal film with a gain medium nanostrip, (ii) a metal film, with nanohole, deposited on a layer of gain medium, and (iii) a nanoparticle coated with a gain medium. The operating frequency of the plasmon laser is close to surface plasmon resonance, hence the cavity size is strongly reduced. The evanescent field of the oscillator stimulates the electron–hole recombination in the gain medium, amplifying the cavity field. With electron–hole occupation probabilities in the relevant energy states in the gain medium just exceeding 50% each, the growth rate exceeds 10¹³  s−¹. The excited cavity mode acts as an oscillatory dipole to emit optical radiation.

Alpha-Fe₂O₃ (α-Fe₂O₃) is cheap and abundant and has potential to be a highly efficient photocatalyst for water splitting. According to the report, there are a huge amount of disposable heating pads being created every year, and the pads are used one time then thrown away. We found that the main product of used heating pads is α-Fe₂O₃. Here, we collect and purify the α-Fe₂O₃ powder in the used heating pads using low power consumption processes. It is shown that the recycled heating pads can be used as a cost-effective photocatalyst for H₂ energy and for decomposition of organic pollutants as well. Additionally, the plasmonic enhanced photocatalysis reaction of α-Fe₂O₃ is also investigated. It is found that H₂ evolution rate can be enhanced 15% using α-Fe₂O₃ nanoparticles coated with a thin Au layer. The degradation of methylene blue can also enhance 12% compared to photocatalyst α-Fe₂O₃ nanoparticles coated without Au layer.

We report a quenching phenomenon within the visible region of the electromagnetic spectrum in the photonic response of a passive Fe₃O₄-silicone elastomer composite film due to magnetically aligned Fe₃O₄ nanoparticles. We performed systematic studies of the polarization dependence, the effect of particle size, and an in- and out-of-plane particle alignment on the optical response of the Fe₃O₄-silicone elastomer composites using a UV/vis/NIR spectrometer. We observed systematic redshifts in the response of the out-of-plane composite films with increasing particle alignment and weight that are attributed to dipole-induced effects. There were no observable shifts in the spectra of the in-plane films, suggesting the orientation of the magnetic dipole and the induced electric dipole play a crucial role in the optical response. A dramatic suppression to near quenching of the photonic response occurred in films containing moderate concentrations of the aligned nanoparticles. This is attributed to the interplay between the intra- and the interparticle dipoles. This occurred even when low magnetic fields were used during the curing process, suggesting that particle alignment and particle size limitation are critical in the manipulation of the photonic properties. A dipole approximation model is used to explain the quenching phenomenon. An active system of such a composite has a potential application in magneto-optic switches.

The theory of the ultrashort laser pulse scattered by metallic nanoparticles in the region of surface plasmon resonances is developed in the framework of kinetic approach. For the spheroidal particles, dependence of the light-scattering cross-section on the shape of the particles, the carrier wave frequency, a pulse duration, and other factors is studied. Additionally, an interaction of small metallic particles with double ultrashort pulse is considered. In this case, the energy scattered by the particles demonstrates oscillating behavior when the time delay between pulses changes. Special attention is paid to the contribution of the particle’s surface when the particle’s size is close to the length of free electron path. The difference between the kinetic approach and Mie theory for nonspherical particles has been shown.

We present a modified asymmetric stripe plasmonic waveguide design for plasmonic integrated input port structures. Such a waveguide shape can significantly increase the surface plasmon polariton (SPP) propagation length. A computational investigation of the waveguide mode analysis, excitation, and guiding is presented as well as SPP propagation length improvement strategies. The proposed structure has the potential to be CMOS compatible and could be used in highly integrated optoelectric circuits.

This PDF file contains the errata for “JNP Vol. 10 Issue 01 Paper JNP-2015-1016-ERR” for JNP Vol. 10 Issue 01