摘要：To diminish the thermal load, two ways, that is, in-band direct pumping and micro-rod crystal, could be adopted at the same time. The efficiency of LD in-band direct-pumping side surface polished micro-rod Nd：YVO_4 laser is numerically analyzed. By optimizing parameters such as crystal length, laser mode radius, pump beam radius, doping concentration and crystal cross-section size, the overall efficiency can reach over 50%. It is found that with micro-rod crystal implemented in the laser oscillator, high overall efficiency LD in-band direct-pumping Nd：YVO_4 laser could be realized. High efficiency combined with low thermal load makes this laser an outstanding scheme for building high-power Nd：YVO_4 lasers.

摘要：A novel evaluation term and a more reasonable criterion,which is described by a new parameter of brightness factor for active large mode area fiber design,are *** brightness factor evaluation method is based on the transverse mode competition mechanism in fiber lasers and *** brightness factor can be seen as a description of fiber general property since it can represent the output laser brightness of the fiber laser system and because of its ability to resist the nonlinear effect.A core-doped active large pitch fiber with a core diameter of 190 μm and a mode-field diameter of180 μm is designed by this method,and the designed fiber allows effective single-mode operation.

摘要：A novel narrow-band filter based on the dual-core doped photonic crystal fiber is *** optimizing structure parameters of the photonic crystal fiber,the index curves of the fundamental modes for the two cores are crossed at 1.55 μm and the wavelength-selective coupling is *** characteristics of the filter are numerically simulated by the full-vector beam propagation *** the simulation results show that the coupling length and the bandwidth of the filter are 16.4 mm and 9 nm at-3 dB loss,*** demonstrates the advantages of the filter with a small size,a low transmission loss and the narrow-band width.

摘要：Design analysis of high core count(36-core,37-core)un-coupled multicore fiber(MCF)using the heterogeneous core has been proposed,to achieve the high spatial efficiency and ultra-low crosstalk(~-81 d B/100 km)under the limited cladding diameter of 300μ*** realize the ultra-low crosstalk level between the neighboring cores,the combination of two crosstalk reduction approaches,trench-assisted(TA)core and propagation direction interleaving(PDI)technique has been *** forward and backward crosstalk characterizations have been studied in heterogeneous MCF with respect to fiber bending radius,wavelength,transmission distance,and core-pitch with both normal step-index and trench-assisted cores under single-mode propagation condition.

摘要：The properties of the linear chirped fiber grating （CFG） which is used in the true time delay unit of the optical beamforming networks （OBFNs） are studied intensively through theoretical analyses and numerical calculations. It is concluded that the dispersion of the CFG is equal to 1/（3Gc）, where G is the chirp coefficient of CFG and c is the light speed. Based on this relationship, a simplified designing process of a CFG which satisfies the requirements of the O13 FN is given. The simula- tion results are coincident with the theoretical conclusions.

摘要：In this letter, the method of direct object-image relationship in normal-view disk-type multiplex holography is adopted for theoretical analysis. The corresponding parameters in hologram fabrication and reconstruction process for both virtual-image and real-image generation are also introduced through nu- merical simulation and experimental results.

摘要：We report the design and fabrication of a novel and fully integrated polymer-based centrifugal microfluidic disc for rapid automatic allergens detection. All essential steps for a single test including flow valving, sequencing, mixing, separation, extraction, and sedimentation for final detection are automatically conducted within 30 min on a centrifugal microfluidic disc. Our design features a siphon-based valving and analyte extraction structure where the released analyte is separated and subsequently extracted by a siphon valve into the detection chamber. Incorporating the siphon valve and a series of capillary valves, we realize automated detection of allergic reaction on a centrifugal microfluidic disc.

摘要：In this paper, we design and characterize a novel small size four-channel biosensor based on the two-dimensional photonic crystal with introducing waveguides and nano-cavities in the hexagonal lattice of air pores in the silicon slab. By removing a group of air pores, waveguides are achieved, and nano-cavities are shaped by modifying the radius of air pores. Highly parallel operation of this biosensor due to the special architecture is the capability of the designed structure. The biomaterials which are suspended in a liquid medium inside nano-cavities cause effective refractive index changes which lead to the resonant wavelength shift in the output terminal. According to results, with increasing the refractive index of nano-cavities, resonant wavelengths shifts to longer values. For biochemical sensing like DNA molecule and protein and for the refractive index detection, this novel designed biosensor can be utilized.

摘要：This paper provides a short overview of the time I spent as a member of the Applied Optics Group at the University of Kent （1985-1989） followed by a review of my research during my time at Cranfield University （1989 to date）.

摘要：This work is about the development of a super low noise amplifier with minimum power consumption and high gain for several wireless *** amplifier operates at frequency bands of 0.9-2.4 GHz and can be used in many applications like Wireless local area network(WLAN),WiFi,Bluetooth,ZigBee and Global System for mobile communications(GSM).This new design can be employed for the IEEE 802.15.4 standard in industrial,scientific and medical(ISM) *** enhancement mode pseudomorphic high electron mobility transistor PHEMT is used here due to its high linearity,better performance and less noisy *** common source inductive degeneration method is employed here to enhance the gain of *** amplifier produces a gain of more than 17 dB and noise figure of about 0.5 *** lower values of S11 and S22 reflect the accuracy of impedance matching network placed at the input and output sides of *** Advance Design System(ADS) is used for the design and simulation *** the layout of design is developed on the FR4 substrate.