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In this paper, an overlapping fan-shaped laser ship navigation system is designed. The system uses red and green lasers to form a fan-shaped safety zone for safe navigation. In order to verify the scientific and rationality of the method, some experiments on laser physics were carried out, including the maximum visible distance of the laser, the sharpness of the laser boundary, and the identifiability of the laser in a complex light environment.On this basis, a laser navigation prototype system was established and a series of ship navigation experiments were carried out on the system.The experimental results show that the overlapping fan-shaped laser navigation system is easy to operate, has high sensitivity, and has a good effect on long-channel navigation, but the method cannot be applied to the entire channel. In addition, lasers can increase navigation distances in poor visibility weather compared to traditional visual navigation methods.

The effect of transverse mode instability has gradually become the primary problem that causes laser beam quality degradation and limits power scaling of high-power fiber lasers. This paper conducts a series of study on the transverse mode instability (TMI) in large mode area (LMA) fiber based on a co-pumped all-fiberized narrow linewidth high power amplification platform. According to the calculation results of the coupled mode equations, the nonlinear coupling strength between the LP01 and LP11 modes of the LMA fiber 25/400 μm is the largest, which directly induces the TMI. In order to suppress the generation and amplification of the LP11 mode at the main amplifier, the fiber coiling method was used as an operational mode filtering technique to achieve mode control. The threshold of TMI increased from 1000 W to 1600 W while reducing the bending radius of the main amplifier gain fiber from 6 cm to 5 cm, and the other output performance of the fiber laser was hardly affected. This provides a powerful experimental reference for us to build an actual narrow linewidth, high power, all-fiberized laser system.

The rapid internationalization of the RMB since 2009 raises many interesting questions, including: Why has this change been so fast? What is the rationality behind this new process? What economic consequences will it produce? What kinds of policies should China adopt to make the process smooth and sustainable? In this paper, we first describe the main developments of RMB internationalization and discuss the rationality of the process, by comparing its benefits and costs. Then, based on the historical experience of the main international currencies, we use a Size-Liquidity-Credibility analytical framework for understanding the determinants of being an international currency. Using this framework, we then provide some policy suggestions for making RMB internationalization a sustainable process.

Strong credit expansion in China after the recent global financial crisis has brought local government financial vehicles (LGFV) into the spotlight. Rapid growth of LGFV has triggered concern about local government indebtedness, banks' asset quality and, more broadly, China's medium-term financial stability and sovereign risk. This paper constructs a unique firm-level dataset to evaluate the country's local government debt. We find an uneven distribution of LGFV, which are concentrated in the coastal areas, and a deterioration of their debt repaying ability from 2010 to 2012. We use principal component analysis (PCA) along with multivariate discriminate analysis (MDA) to identify the credit risk of LGFV based on conventional financial variables as well as local governments' fiscal status. We also estimate the safe boundaries of debt bearing at the provincial government level. The estimations reveal more severe local government debt risks in the middle-western provinces and higher risks associated with LGFV at the municipal and county levels. Although it is very unlikely that there will be a national debt crisis in China, the high risk of LGFV should be noted and effectively controlled by improving the fiscal transparency of local governments and reforming the fiscal system.

China's large current account surpluses not only destabilize its own macroeconomic conditions, but are also a focal point for global rebalancing discussions. Existing explanations by the literature fail either to account for the recent surge or to offer actionablepolicy responses. In this study, we propose an alternative hypothesis: asymmetric market liberalization and associated cost distortions. These distortions are producer subsidy equivalents, which contributed to both extraordinary growth performance and the growing structural imbalances. Our rough estimates of such factor cost distortions offer some explanations for recent movements of the current account. We argue that China needs to adopt a comprehensive reform package to rebalance its economy.

Effect of temperature gradient and uniform temperature on tracking performance of reflectors in periscopic laser communication terminals was studied. Zernike polynomials on elliptical area were used to fit wave-front aberration of elliptical reflectors in periscopic laser communication terminals due to temperature distribution. RMS value of the thermal deformation, tracking error and intensity on detectors degradation at receiving terminals caused by thermal deformation were studied in inter-satellite laser communication system. From the result we can know that effect of temperature gradient is the move of peak intensity and a little degradation. The tracking error reaches 2.9μrad when temperature gradient is 14°C/m. The uniform temperature will cause variation of intensity distribution on focus plane of detectors. When the difference between uniform temperature and reference temperature is small, the astigmatism causing by thermal distortion is very important. As the difference becomes bigger, the high-order modes of Zernike polynomials become very important. The distribution of intensity becomes irregular and the area is very big. This will reduce the tracking performance of detectors. This work will contribute to the thermal control of elliptical reflectors in periscopic laser communication terminals on satellites in orbit.

The technology of compounding LIDAR with visible imaging topographic mapping in space is firstly proposed in this paper. We introduce the design project of integration for laser and visible system in detail, and create the geometrical model for LIDAR Compounded with Visible Imaging Topographic Mapping. Using simultaneous adjustment test with true satellite data, it is verified that the system of LIDAR compounded with visible Imaging topographic mapping meets the designed technology index.

This paper analyses the financial distortions – growth nexus in China using a tractable general equilibrium modelling approach in which heterogeneous private and state-owned firms interact. The focal points of the model are financial frictions and reallocations of factors of production across firms. The calibrated version of the model elicits the important message that the adoption of a comprehensive financial market reform package abolishing financial distortions will lead to substantial output gains. Thus, structural policies leading to more efficient allocation of factors of production will remain a key policy challenge in China in the years to come.

A high optical signal-to-noise ratio (OSNR) single-frequency 2 μm Brillouin fiber laser (BFL) with watt-level output and high transfer efficiency is demonstrated for the first time to the best of our knowledge. The Brillouin pump is constructed with a two-stage thulium-doped fiber amplifier (TDFA) seeded by a 2 μm laser diode, providing 4.02 W average power with 1 MHz linewidth. Using an optimized length of 14 m for the Brillouin ring cavity, the BFL works stably in single-mode region with 8 kHz linewidth because of the linewidth narrowing effect. The transfer efficiency is 51% with 1.08 W output power and 62 dB OSNR for 3.22 W pump power.

Performance of on-off keying (OOK), digital pulse interval modulation (DPIM), and pulse position modulation (PPM) schemes are researched for ground-to-satellite laser uplink communications. Packet error rates of these modulation systems are compared, with consideration of the combined effect of intensity fluctuation and beam wander. Based on the numerical results, performances of different modulation systems are discussed. Optimum divergence angle and transmitted beam radius of different modulation systems are indicated and the relations of the transmitted laser power to them are analyzed. This work can be helpful for modulation scheme selection and system design in ground-to-satellite laser uplink communications.

Despite the increasing recognition that the renminbi (RMB) may eventually become a key global currency, several important questions remain to be answered. This paper analyzes the benefits and costs of the RMB becoming an international currency. The benefits include reduced exchange risk, promotion of the development of the financial market, and expansion of firms in the People’s Republic of China. The costs include general costs, which complicate monetary policy and exchange rate policy, and several transitional risks. The study argues that the benefits of RMB internationalization should surpass the costs, particularly in the long run, and provides comprehensive policy choices for a sustainable process of RMB internationalization.

The current account surplus of the People’s Republic of China (PRC) has drawn much foreign and domestic attention. This paper focuses on the reasons and remedies for the PRC’s current account surpluses. Rather than deploying the standard explanations, we argue that asymmetric market liberalization and the related factor market distortion is the root reason for the PRC’s external imbalances. These cost distortions have artificially lowered PRC production costs, raised profits, and improved their products’ international competitiveness which has not only stimulated the economy, but also brought about severe structural risks. We completed a crude estimation for factor cost distortions in the PRC during 2000-2009 which matched its current account surpluses quite well. In order to rebalance the economy, we recommend that the PRC should adopt a comprehensive reform package focusing on removing the factor market distortions.

The current account surplus of the People’s Republic of China (PRC) has drawn much foreign and domestic attention. This paper focuses on the reasons and remedies for the PRC’s current account surpluses. Rather than deploying the standard explanations, we argue that asymmetric market liberalization and the related factor market distortion is the root reason for the PRC’s external imbalances. These cost distortions have artificially lowered PRC production costs, raised profits, and improved their products’ international competitiveness which has not only stimulated the economy, but also brought about severe structural risks. We completed a crude estimation for factor cost distortions in the PRC during 2000–2009 which matched its current account surpluses quite well. In order to rebalance the economy, we recommend that the PRC should adopt a comprehensive reform package focusing on removing the factor market distortions.

Space zoom reflector (SZR) is a key component in many applications of intending super-range deep space optical communication in interstellar task, laser antimissile etc. In this article, the demand of SZR has been analyzed, and a new plane machining method has been brought forward, which uses load on edge flexural torque to adjust the focal length and micrometer mechanisms to implement the precise closed-loop control. Firstly the study discusses the feasibility of using entire distortion to obtain steady focus in mechanics of elasticity, and then advances the techniques of its realization and methods of space combination and unfolding. Finally it describes the methods on how to adjust the SZR's focus, control tracking and pointing directions and increase its precision. Compared with SZRs made in other methods, this SZR is easier to machining, to adjust the focus and to be applied in the space combination with lower cost. All these merits give it a very good prospect.