Nanolasers Research Articles

Review of: "Nano lasers work on length scales 1000 times smaller than the thickness of a human hair"

Review of: "Nano lasers work on length scales 1000 times smaller than the thickness of a human hair"

Large-area superconducting nanowire arrays fabricated by nano laser direct writing

We report on the fabrication, structural, and electrical transport characterizations of superconducting nanowire arrays based on nano-laser direct writing (NLDW). The thermal excitation-induced micro/nano fabrication based on the interactions between NLDW and superconducting Nb films was experimentally analyzed and simulated. Experimentally, the arrays of superconducting nanowires have an area of 190 × 190 μm2 with a critical transition temperature Tc of 7.8 K and a critical current density Jc of 20.8 MA cm−2 at 4.0 K. The width and arrangement of the nanowires are precisely controlled, exhibiting a minimal loss of 0.6 K in Tc and excellent Jc after LDW. The width of superconducting nanowires could be further optimized by adjusting parameters such as laser power, irradiation gap, and delay of points. Compared with electron beam lithography and focused ion beam, to some extent, the nanowires fabrication process based on NLDW provides a more efficient and cost-effective path for fabricating large-area superconducting circuits and devices.

Random Numbers Generated Based on Dual-Channel Chaotic Light

This paper presents a chaotic system based on novel semiconductor nanolasers (NLs), systematically analyzing its chaotic region and investigating the influence of key parameters on the unpredictability of chaotic output. This study found that under optical feedback conditions, NLs generate chaos across a wide range of feedback parameters, with the highly unpredictable region completely overlapping with the chaotic region. Further injection into the slave lasers enhances the chaotic output, expanding the range of unpredictability. Additionally, we analyzed the impact of internal parameter mismatch on the complexity of chaotic signals and found it to be similar to the scenario when parameters are matched. Using this chaotic system as an entropy source, we constructed a random number generator (RNG) and investigated the effects of internal parameters mismatch and differences in the injection parameters on the generator’s performance. The simulation results show that the RNG performs well under different parameter settings, and the generated random sequences pass all random number tests successfully. Therefore, this chaotic system can yield a high-complexity chaotic light source with appropriate parameter selection, and when combined with effective post-processing, it can generate high-quality random numbers. This is crucial for advancing the realization of small-sized, high-randomness RNGs.

Thermal excitation-induced micro/nano fabrication and material modification of superconducting Nb films

We report the thermal excitation-induced material modification and micro/nano fabrication based on the interactions between nano laser direct writing (NLDW) and superconducting films experimentally and by simulation. The niobium (Nb) films with a critical temperature of 9 K were deposited on silicon substrate via sputtering with the thickness of around 50 nm. The boundary between material modification and micro/nano fabrication was verified by changing the interaction time and laser power continuously. Specifically, as the laser power was fixed at 250 mW and the interaction time below 440 ns, the interaction is material modification. With the increasing interaction time further, the Nb films were etched away. As the interaction time was fixed at 500 ns and the laser power below 200 mW, the interaction is material modification too. With the increasing of laser power further, the Nb films were etched away. In the experiment, the oxygen content and current–voltage characteristic (IVCs) before and after laser irradiation were displayed to verify the material modification, which is in line with the simulation results. Considering the 50 nm resolution of NLDW, in the material modification region, one could trim trilayer junctions, tune shunt resistors, or adjust critical currents, etc. In the micro/nano fabrication region, one could fabricate various devices and exploit the properties of high spatial resolution, high flexibility, and fast processing.

High-quality random bit generation based on a cascade-coupled nano-laser system

In this paper, a novel method is proposed to generate high-quality chaotic signals using three cascade-coupled nano-lasers (NLs), and generate high-speed, high-quality random number sequences. The master NL (MNL) is subjected to optical feedback, and its output is injected into the intermediate NL (INL), which is further injected into the slave NL (SNL). In the simulation, we first adjust proper parameters so that the SNL generates a chaotic signal with a large bandwidth and time-delay signature concealment. After performing self-delayed differential processing on the chaotic signal, and utilizing an 8-bit analog-to-digital converter for sampling and quantization, followed by extraction of the m-bits least significant bit, the final random bit sequence is obtained. Finally, we use NIST SP 800-22 to test the generated random numbers. The results demonstrate that the obtained random number sequence successfully passed all tests specified by NIST SP 800-22.

Time-Delay Signature Suppression and Communications of Nanolaser Based on Phase Conjugate Feedback

The nonlinear dynamics of nanolasers (NLs), an important component of optical sources, has received much attention. However, there is a lack of in-depth research into the high-quality chaotic output of NLs and their applications in chaotic secure communications. In this paper, we make the NLs generate broadband chaotic signals whose time-delay signatures (TDS) are completely hidden by a phase conjugate feedback structure. And in the two-channel communication scheme, we make the NLs achieve a combination of a low-latency high degree of synchronization and two-channel transmission technique, which enhances the security of message encryption and decryption. We also investigate the effects of system parameters, Purcell factor F, spontaneous emission coupling factor β, and bias current I on the TDS, as well as the effects of parameter mismatch and injection parameters on chaos synchronization and message recovery. The results show that the phase conjugate feedback-based NLs can achieve the suppression of the TDS within a certain parameter range, and it can achieve high-quality synchronization and enhance the security of chaotic communication under appropriate injection conditions.

Bidirectional Chaotic Synchronization Communication of Closed-Loop Mutually Coupled Nano-Lasers

It is well known that the dynamical characteristics of nano-lasers (NLs) have been extensively studied, but there is limited research on chaotic synchronization communication. In this paper, we propose a closed-loop system of mutually coupled NLs. Firstly, the autocorrelation function is employed to evaluate the capability of the system to conceal the time-delayed signature (TDS), and then, based on this, we specifically analyze the effects of the injection strength, frequency detuning, and parameter mismatch of two NLs on the chaotic synchronization performance, as well as the bidirectional communication. The detailed studies indicate that the proposed closed-loop mutually coupled system based on NLs can achieve high-quality chaotic synchronization with a low TDS and large bandwidth. In addition, the system maintains high-quality chaotic synchronization and communication performance even under significant parameter mismatch.

Nano Lasers (Continuous Waves or CW) Structure and Function

Nano Lasers (Continuous Waves or CW) Structure and Function

The Wavelength of The Output Beam and The Wavelength of The Output Beam of Nano Laser

The Wavelength of The Output Beam and The Wavelength of The Output Beam of Nano Laser

Dynamics and Concealment of Time-Delay Signature in Mutually Coupled Nano-Laser Chaotic Systems

It is well known that nano-lasers (NLs), as important optical components, have attracted widespread attention for their output characteristics. In this paper, the dynamic behavior and time-delay concealment properties of NLs mutually coupled in open-loop, semi-open-loop, and closed-loop structures have been numerically investigated. We employ bifurcation diagrams and 0–1 chaos tests in our simulations to quantitatively analyze the dynamic properties of the system and introduce the autocorrelation function to evaluate the ability of the system to conceal the time-delay signature (TDS). In the meantime, the effects of the NL parameters and the controllable variables of the system on the TDS are studied. The results indicate that, compared with an open-loop structure without feedback, the mutual coupling scheme with added feedback is beneficial for the system to output high-quality chaotic signals. Furthermore, selecting a moderate Purcell factor F and a smaller spontaneous emission coupling factor β can achieve TDS concealment over a wider parameter range of injection intensity and frequency detuning.

Interaction of plasmonic bound states in the continuum

Bound states in continuum (BICs) are believed to have the ability to achieve high quality factor (Q factor) resonances, which is very important for plasmonics. However, the study of plasmonic BICs is not sufficient. Herein, we design and fabricate a metal−insulator−metal (MIM) metasurface and demonstrate a one-dimensional plasmonic BIC experimentally. The even-order localized surface plasmon resonance (LSPR) modes have even parity at normal incidence. The symmetry-protected BIC can be achieved at Γ point. The band structure can be tuned by strong coupling between the localized plasmonic resonance and plasmonic lattice mode. Interestingly, two of the hybrid modes are also BICs. Although BICs cannot interact with the far field, we successfully demonstrate BIC splitting through far-field excitation. By further tuning the pitch of the MIM grating, the Friedrich–Wintgen BIC is also observed. Finally, we propose and preliminarily demonstrate an ultrathin bandpass spatial filter. These findings provide a new platform to study optical multipole BICs and can have applications in fields such as nano lasers, ultrasensitive sensors, filters, nonlinearity enhancement, and quantum optics.

Inverse-cavity structure for low-threshold miniature lasers

Creating micro and nano lasers, high threshold gain is an inherent problem that have critically restricted their great technological potentials. Here, we propose an inverse-cavity laser structure where its threshold gain in the shortest-cavity regime is order-of-magnitude lower than the conventional cavity configurations. In the proposed structure, a resonant feedback mechanism efficiently transfers external optical gain to the cavity mode at a higher rate for a shorter cavity, hence resulting in the threshold gain reducing with decreasing cavity length in stark contrast to the conventional cavity structures. We provide a fundamental theory and rigorous numerical analyses confirming the feasibility of the proposed structure. Remarkably, the threshold gain reduces down by a factor ~ 10−3 for a vertical-cavity surface-emitting laser structure and ~ 0.17 for a lattice-plasmonic nanocavity structure. Therefore, the proposed approach may produce extremely efficient miniature lasers desirable for variety of applications potentially beyond the present limitations.

Single-cell mass spectrometry imaging of TiO2 nanoparticles with subcellular resolution

Nanoparticles (NPs) show great potentials in biomedicine and therapeutics fields with the specific physical and chemical properties. As the physiological functions and toxicity of NPs depend heavily on their intracellular locations, the distribution of NPs within single cells presents to be of vital importance. Herein, a nano laser probe (NLP)-based mass spectrometry imaging (MSI) technique was utilized for visualization of titanium dioxide nanoparticles (TiO 2 NPs) within single cells with an imaging pixel size of 500 nm. Using a micro-lensed fiber for laser introduction, the sampling crater diameter of about 420 nm was obtained. In addition, images of all titanium isotopes and their oxides were acquired for the same cells. The MSI results indicate that TiO 2 NPs simply accumulate in lysosomes, which is in accordance with the results of laser scanning confocal microscopy (LSCM). With a great feasibility and reliability, this technique has great potential for the research of NPs in biomedicine and clinical fields.

Editorial

This is the first issue of the Engineering Manufacturing Letters (EML). The journal is published by the University of Porto. The journal is expected to receive submissions from a wide range of industries such as transportation (automotive, rail, aeronautical and marine), packaging, electronics, sports, etc. In addition, intense research on this subject is also performed in academic contexts, and contributions by higher learning institutions and research centers are also expected. This journal will accept submissions on additive manufacturing, vacuum assisted high pressure die casting, semi-solid metal casting, compressive and tensile forming processes, micro and nano machining, nanocomposite manufacturing, adhesive bonding, laser cutting and joining, etc. Subtopics include modelling and optimization of manufacture processes, design for manufacturing strategies, development of new manufacturing technologies, design of novel manufacturing equipment, comparative case studies, cost and quality analysis, ecological aspects and destructive and non-destructive testing of manufactured components.

Clinical and radiological of the effects of two different implant surfaces on marginal tissues

Aim: In this study, our aim is to compare the effects of dental implants with nano laser excimer technology surface (NLE) and dental implant surfaces (MTX) with micro-roughened surface on marginal tissues with clinical and radiological data.
 Methodology: A total of 117 dental implants were followed clinically and radiologically. Clinically; Plaque index (silness-leöe), bleeding index in boring, pocket depth were evaluated and recorded 1 week after the insertion of the healing cap, 3 months, 6 months and 12 months after the end of the prosthesis. In the same periods, periapical x-rays were taken with the Rinn Holder method and the amount of marginal bone loss was measured. The data were analyzed with IBM SPSS Statistics Version 22 package program.
 Results: There was no loss in the implants included in the study. There was no statistically significant difference between the groups in terms of plaque index, bleeding index values (p>0,05). However, the pocket depth of the dental implant group with nano laser excimer technology surface is significantly lower than the micro-roughened surface group. There are statistically significant differences between the groups in terms of radiological marginal bone loss at 0, 3, 6, and 12 months (p<0,05). Radiological marginal bone loss values ​​of the micro-roughened surface group at 0, 3, 6, and 12 months were significantly lower compared to the same periods of the nano laser excimer technology group.
 Conclusion: It has been determined that the surface properties of dental implants can be effective on marginal tissues. In addition, we believe that routine checks by dentists who perform dental implant applications will increase the success of dental implants.
 
 How to cite this article: Bingül MB, Gülsün B. Clinical and radiological of the effects of two different implant surfaces on marginal tissues. Int Dent Res 2021;11(Suppl.1):152-9. https://doi.org/10.5577/intdentres.2021.vol11.suppl1.23
 
 
 Linguistic Revision: The English in this manuscript has been checked by at least two professional editors, both native speakers of English.

Investigation the dynamic of nano quantum cascade lasers with optoelectronics feedback


 
 
 
 In this paper, a theoretical investigation of negative optoelectronic feedback study in Nano quantum cascade lasers is presented. The present rate equation model has been modified to include the nano laser factors such as the Purcell factor and the spontaneous emission factor. The results indicate that the present rate equation model can be using to study the effect of Purcell factor and the spontaneous emission factor on the negative optoelectronic feedback in Nano quantum cascade lasers. It is found that the increase in Purcell factor value leads to increase in photon number and decrease the carrier number in all quantum states. Also, the dynamic of photon number (S) tends to stable at constant value with the increase of Purcell effect i.e. there is small variation in photon number and carrier number( , , ). The decreases in enhanced spontaneous emission factor value leads to increases in carrier number and decreases the photon number and we note small variation in these values.
 
 
 

Novel Difolate Targeting Nano-Level Ultrasound Contrast Agent for Therapy of Breast Cancer Tumor Cells

ABSTRACTA new type of difolate targeting nano-level ultrasound contrast agent ((folate molecule, FOL)2-TUAs) was prepared, so as to investigate its targeted binding effect with human breast cancer mammary carcinoma cells (MCF-7) in vitro. L-2-aminoadipic acid (L-2-AD) as a branch unit was inserted at the hydroxyl end of distearoyl phosphatidylethanolamine (DISP)-PEG2000-COOH to construct a tree structure. At this time, the free hydroxyl group in the distearoyl phosphatidylethanolamine (DISP)-PEG2000-COOH structure modified the FOL with the help of N-Hydroxysuccinimide/N,N'-dicyclohexylcarbodiimide (NHS/DCC). Each 1,2-distearoyl-sn-glycero-3-phosphoethanolamine-N-[methoxy(polyethylene glycol)-2000] (DISP-PEG2000) connected two FOLs to generate difolate targeted nanomaterials. Nano laser particle size (PS) and Zeta potential analyzer (ZPA) were applied to analyze the physical characteristics of the material such as PS and dispersion, and the enhanced development effect in vitro was detected by the ultrasonic diagnostic instrument. Besides, the targeted binding ability of the contrast agent based on this material to folate receptor (FR) overexpressing MCF-7 cells was analyzed by flow cytometry (FCM) and fluorescence microscope. In the experiment, hydrogen-1 nuclear magnetic resonance (1H NMR) demonstrated that (FOL)2-TUAs was successfully synthesized. The surface of this material was round and uniformly distributed without aggregation. According to the relative number of FOL molecules, non-targeted nano-agent (U-TUA), monofolate targeted nano-agent (FOL-TUA), and difolate targeted nano-agent ((FOL)2-TUA) were obtained. The in vitro imaging showed that different materials exhibited enhanced imaging effects in ultrasonic diagnostic equipment. FCM and fluorescence microscopy both indicated that the difolate TUA could achieve a good binding to MCF-7 cells. Most of the nano-agents were attached to the cell membrane, surrounded by red fluorophore, namely increasing the FOL content of DISP-PEG2000 chain could enhance the targeted binding ability of tumor cells.

The single layer nano-laser with nanohole arrays prepared by three beams laser interference ablation on Ga0.1Co0.5ZnSe0.4 films

Nano-laser has a widely application in many fields such as biosensors, quantum memory, energy harvesting, photonic applications. However, there are still some problems in current preparation process of nano-laser device such as complex fabrication methods and high cost. Meanwhile, the size of nano-lasers has always been a challenge in the fabrication, and single-layer nano-film lasers have rarely been reported. Here, we propose a method of three beams laser interference ablation on Ga0.1Co0.5ZnSe0.4 film. The nanohole arrays with a period of 1 μm are fabricated. The film of Ga0.1Co0.5ZnSe0.4 used for ablation is prepared via Pulse Laser Deposition (PLD) technology. Then, the structure and components of the film are characterized by X-Ray Diffraction (XRD) and Raman spectrum. The real existence and chemical valence state of the Co, Ga, Zn and Se elements are proved by X-Ray Photoelectron Spectroscopy (XPS). The stoichiometry of thin film is confirmed by X-Ray Fluorescence Spectrometer (XRF). The morphology and cross section of the nanohole arrays is demonstrated by Scanning Electron Microscope (SEM), illustrating the depth of hole around 760 nm. To gain more understanding about the laser emission, the single-layer film with nanohole structure is simulated by Finite Difference Time Domain (FDTD) solutions. Finally, the PL spectrum reveals a 903 nm-laser emission at near-infrared. All the results show that a simple, efficient and low-cost single-layer nano laser film is presented.

Preparation of Ta(Ph)‐Fe/AP Composite Microspheres by Ultrasonic Spray Drying and Characterization of Their Catalytic Properties

AbstractIn this study, the ultrasonic spray drying technology was applied to prepare composite microspheres of catalyst (Ta−Fe, Ph−Fe) and AP. The surface morphology of the two composite microspheres was characterized by scanning electron microscopy (SEM). Their particle size distribution characteristics were tested by a nano laser particle size analyzer. The results showed that the spray drying technology can uniformly compound the AP and the catalyst into spherical particles. The thermal decomposition process of Ta(Ph)‐Fe/AP composite microspheres were tested by differential scanning calorimetry (DSC). The DSC data demonstrated that Ta(Ph)‐Fe/AP composite microsphere had a very good catalytic effect and significantly promoted the thermal decomposition process of AP. In addition, the catalytic mechanism was discussed by calculating the change in activation energy. Compared with the raw AP, the activation energies of the Ta−Fe/AP and Ph−Fe/AP composite microspheres were reduced by 18.5 kJ/mol and 28.1 kJ/mol, respectively.

Lasing mode regulation in zinc oxide microcavity

As a short-wave optoelectronic device, ultraviolet (UV) nano laser has a broad prospect in the fields of electronics, information, communication, environmental monitoring and biomedical testing. Zinc oxide (ZnO) microcavities show significant advantages in the realization of UV laser with low threshold and high quality factor. Resonance mode regulation and single-mode realization are the key problems for the practical application in ZnO microcavity UV laser. Based on the basic theory of microcavity mode, this paper reviews the progress of lasing mode regulation of ZnO microcavity according to different regulation mechanisms. Firstly, the important progress of traditional static regulated methods, such as cavity structure control and vernier effect, in the lasing mode effective regulation of ZnO microcavity is discussed. Secondly, the dynamic regulation of lasing mode in ZnO microcavity is realized by modulating effective refractive index through piezoelectric or electro-optic physical effects. Finally, the latest progress of surface plasmon effect in the realization of micro and nano cavity laser regulation is summarized. Many traditional methods, with the construction of distributed Bragg reflector (DBR) or distributed feedback (DFB) structure, cavity size control, vernier effect and so on, have been used to realize the lasing mode effective regulation and single-mode-lasing output of ZnO microcavity. However, these traditional methods are only suitable for the pre-designed microcavity structure, and they are highly dependent on the complex micro processing technology. Reducing the size of the cavity will inhibit the acquisition of optical gain, resulting in the increase of optical loss and laser threshold. In addition, these mode regulations are not reversible. In order to solve these problems, many scholars have taken various effective measures. The introduction of surface plasmon, a new physical effect, can make the optical field of ZnO microcavity get better confinement, so as to improve the microcavity gain and reduce the lasing threshold. Based on piezoelectric effect or electro-optic effect, the effective refractive index of ZnO can be regulated, and the dynamic regulation of ZnO microcavity mode can be realized by introducing external stress or external electric field. In addition, the combination of surface plasmon and ZnO nanocavity not only breaks the diffraction limit in size, but also regulates the laser mode in intensity, threshold and mode volume, which provides more theoretical basis and reference value for the future pursuit of nano laser with lower threshold, stronger intensity and smaller mode volume. These methods are not only suitable for ZnO UV laser, but also provide reference for other materials and other band microcavity laser.