Tailoring a nanofiber for enhanced photon emission and coupling efficiency from single quantum emitters

We present a novel approach to enhance the spontaneous emission rate of single quantum emitters in an optical nanofiber-based cavity by introducing a narrow air-filled groove into the cavity. Our results show that the Purcell factor for single quantum emitters located inside the groove of the nanofiber-based cavity can be at least six times greater than that for such an emitter on the fiber surface when using an optimized cavity mode and groove width. Moreover, the coupling efficiency of single quantum emitters into the guided mode of this nanofiber-based cavity can reach up to $\sim$ 80 $\%$ with only 35 cavity-grating periods. This new system has the potential to act as an all-fiber platform to realize efficient coupling of photons from single emitters into an optical fiber for quantum information applications

Optical nanofiber-based cavity induced by periodic air-nanohole arrays

We experimentally realized an optical nanofiber-based cavity by combining a 1-D photonic crystal and Bragg grating structures. The cavity morphology comprises a periodic, triplex air-cube introduced at the waist of the nanofiber. The cavity has been theoretically characterized using FDTD simulations to obtain the reflection and transmission spectra. We have also experimentally measured the transmission spectra and a Q-factor of ~784(87) for a very short periodic structure has been observed. The structure provides strong confinement of the cavity field and its potential for optical network integration makes it an ideal candidate for use in nanophotonic and quantum information systems

Telecom-wavelength spectra of a Rydberg state in a hot vapor

We study telecom-wavelength spectra of a Rydberg state in an atomic vapor with a three-photon excitation scheme. Two lasers of 780 nm and 776 nm are used to pump Rubidium-85 atoms in a vapor cell to the $5D_{\mathrm{5/2}}$ state, from which a probe beam of 1292 nm in the O-band telecommunication wavelength drives a transition to the $21F_{\mathrm{7/2}}$ Rydberg state. We investigate the probe spectra over the power of pump lasers. The simulation based on a 4-level theoretical model captures the main features of the experimental results. This spectroscopic study paves the way for future experiments of making a direct link between fiber optics and radio transmission via Rydberg atoms.Comment: 5 pages and 4 figure

Projectional Coderivatives and Calculus Rules

This paper is devoted to the study of a newly introduced tool, projectional coderivatives and the corresponding calculus rules in finite dimensions. We show that when the restricted set has some nice properties, more specifically, is a smooth manifold, the projectional coderivative can be refined as a fixed-point expression. We will also improve the generalized Mordukhovich criterion to give a complete characterization of the relative Lipschitz-like property under such a setting. Chain rules and sum rules are obtained to facilitate the application of the tool to a wider range of problems

Supply Chain Joint Inventory Management and Cost Optimization Based on Ant Colony Algorithm and Fuzzy Model

With the advancement of the marketization process, inventory management has transformed from a single backup protection function to an essential function for enterprises, which helps to survive and develop. Inventory control in supply chain management is the important content of supply chain management. The new management mode makes inventory management present many new characteristics and problems compared with traditional inventory management. From the view of system theory and integration theory, it is imperative to re-examine the problem of inventory control, put forward new inventory management strategies adapted to integrated supply chain management, and improve the integration of the whole supply chain, which can enhance the agility and market response speed of enterprises. Based on the in-depth study of the joint inventory management model, this paper analyzed the current situation of the joint inventory management to optimize the inventory. In view of the achievements and shortcomings of the current research, a more systematic and improved optimization model of the supply chain inventory was proposed by using the basic ideas of ant colony algorithm and fuzzy model

Adenoma Detection Rate in Asymptomatic Patients with Positive Fecal Immunochemical Tests

Background and Aims The adenoma detection rate (ADR) is a powerful measure of screening colonoscopy quality. Patients who undergo colonoscopy for the evaluation of a positive fecal immunochemical test (FIT) have increased prevalence of colorectal neoplasia, but it is not known whether separate quality benchmarks are required. The aim of this study was to compare the conventional ADR to the ADR of colonoscopies performed for the evaluation of positive FIT, in asymptomatic average-risk patients. Methods Patients ≥ 50 years old who underwent colonoscopy for the evaluation of a positive FIT between January 1, 2013, and July 31, 2014, at a tertiary Veterans Affairs Medical Center were identified. FIT performed for any indication other than average-risk screening was excluded. The comparison group included average-risk patients ≥ 50 years old undergoing screening colonoscopy during the same time frame. The two groups were compared for ADR, advanced neoplasm [adenoma ≥ 10 mm, tubulovillous, high-grade dysplasia, CRC, sessile serrated polyp (SSP) ≥ 10 mm], CRC, and SSP detection after propensity score adjustment using a logistic regression model adjusted for endoscopist. Results There were 207 patients in the FIT group and 601 in the screening colonoscopy comparison group. After propensity score adjustment, ADR (72.9 vs. 50.0%, p = 0.003), number of adenomas per colonoscopy (3.3 ± 3.6 vs. 1.4 ± 2.3, p = 0.033), and advanced neoplasm detection rate (32.4 vs. 11.0%, p < 0.0001) were significantly higher in the FIT group. There were no significant differences in the number of CRC and the SSP detection rate. Conclusions In this cohort of average-risk Veterans, the ADR of colonoscopies performed for the evaluation of a positive FIT was higher than the ADR of screening colonoscopies. Patients with a positive FIT also had significantly more adenomas per colonoscopy and advanced neoplasms. These findings suggest that the quality of colonoscopies performed for a positive FIT is insufficiently assessed by the conventional ADR and requires additional quality metrics

Corporate Credit Rating: A Survey

Corporate credit rating (CCR) plays a very important role in the process of contemporary economic and social development. How to use credit rating methods for enterprises has always been a problem worthy of discussion. Through reading and studying the relevant literature at home and abroad, this paper makes a systematic survey of CCR. This paper combs the context of the development of CCR methods from the three levels: statistical models, machine learning models and neural network models, summarizes the common databases of CCR, and deeply compares the advantages and disadvantages of the models. Finally, this paper summarizes the problems existing in the current research and prospects the future of CCR. Compared with the existing review of CCR, this paper expounds and analyzes the progress of neural network model in this field in recent years.Comment: 11 page