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：A complex-coupled DFB laser with sampled grating has been designed and fabricated. The method uses the ＋ 1 st order reflection of the sampled grating for laser single-mode operation. The typical threshold current of the sampled grating based DFB laser is 25 mA, and the optical output is about 10 mW at the injected current of 100 mA. The lasing wavelength of the device is 1.5385 μm, which is the ＋1 st order wavelength of the sampled grating.

摘要：Multispectral and polarization cameras that can simultaneously acquire the spatial,spectral,and polarization characteristics of an object have considerable potential applications in target detection,biomedical imaging,and remote *** this work,we develop a common-aperture optical system that can capture multispectral and polarization *** off-axis three-mirror optical system is mounted on the front end of the proposed system and used as a common-aperture telescope in the visible light(400 nm-750 nm)and long-wave infrared(LWIR,8μm-12μm)*** system can maintain a wide field of view(4.5°)and it can demonstrate an enhanced identification *** off-axis three-mirror system gets rid of central obscuration while further yielding stable system resolution and *** that has passed through the front-end common-aperture reflection system is divided into the visible light and LWIR waveband by a *** two wavebands then converge on two detectors through two groups of *** simulation results indicate that the proposed system can obtain clear images in each waveband to meet the diverse imaging requirements.

摘要：Using compressive sensing for imaging has many applications, and it is an important branch of computational *** this Letter, freeform surfaces are introduced in the hardware optical system design of a compressive sensing imager. The system works under the medium wave infrared band and realizes a 16× compression with a field-of-view of 7.5°× 6°. Good imaging performance is achieved in both the entire system and the freeform objective optics. Compared with the system using all spherical lenses, the volume of the freeform system is about 1/3 smaller, and the total transmittance is about 56%higher, which shows the benefits of using freeform surfaces for compressive sensing and computational imaging.

摘要：High-power fiber lasers have experienced a dramatic development over the last *** increasing the output power needs an upscaling of the fiber mode area,while maintaining a single-mode ***,we propose an all-solid anti-resonant fiber(ARF)structure,which ensures single-mode operation in broadband by resonantly coupling higherorder modes into the cladding.A series of fibers with core sizes ranging from 40 to 100µm are proposed exhibiting maximum mode area exceeding 5000µ*** simulations show this resonant coupling scheme provides a higher-order mode(mainly TE01,TM01,and HE21)suppression ratio of more than 20 dB,while keeping the fundamental mode loss lower than 1 dB/*** proposed structure also exhibits high tolerance for core index depression.

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.

摘要：The orbitofrontal cortex(OFC)is involved in diverse brain functions via its extensive projections to multiple target *** is a growing understanding of the overall outputs of the OFC at the population level,but reports of the projection patterns of individual OFC neurons across different cortical layers remain ***,by combining neuronal sparse and bright labeling with a whole-brain florescence imaging system(fMOST),we obtained an uninterrupted three-dimensional whole-brain dataset and achieved the full morphological reconstruction of 25 OFC pyramidal *** compared the wholebrain projection targets of these individual OFC neurons in different cortical layers as well as in the same cortical *** found cortical layer-dependent projections characterized by divergent patterns for information *** study not only provides a structural basis for understanding the principles of laminar organizations in the OFC,but also provides clues for future functional and behavioral studies on OFC pyramidal neurons.

摘要：The large refractive index difference between Si and SiO2 makes it possible to realize ultrasmall photonic integrated circuits. A 5×5 ultracompact arrayed waveguide grating multiplexer based on 500×250 nm Si nanowire waveguides is designed and fabricated by using the technologies of E-beam writing and amorphous-Si deposition. The mea- sured channel spacing is about 1.5 nm (close to the design value) and the channel crosstalk is about –8 dB.

摘要：二维范德瓦尔斯异质结构广泛应用于光电化学(PEC)型光电探测器、水分解和太阳能电池等光电器件中.其中,Ⅰ型异质结构对于设计新型光电器件至关重要,然而其能带排列对光电响应的影响尚不清楚.本文利用两步物理气相沉积法构建了Ⅰ型SnSe_(2)/ZnS异质结构,并通过紫外光电子能谱和X射线光电子能谱进行了验证.基于Ⅰ型SnSe_(2)/ZnS异质结构的光电化学探测器在紫外可见范围内具有良好的光响应、高稳定性和高灵敏度.SnSe_(2)/ZnS的光响应可达172.60μA W^(-1),分别是单一ZnS和SnSe_(2)样品的7.4和2.0倍.并且,SnSe_(2)/ZnS异质结构具有较高的光电催化分解水活性,在2 h内总产氢量可达81.25μmol ***_(2)/ZnS异质结优异的光电探测和水分解性能主要源于其更高的光利用率和高效电荷传输的协同作用.本工作为通过构建Ⅰ型异质结构来提高光电响应并设计高性能光电探测器和水分解等光电器件提供了一种新方法.

摘要：To implement high quality tunneling injection quantum dot lasers, effects of primary factors on performance of the tunneling injection quantum dot lasers were investigated. The considered factors were tunneling probability, tun- neling time and carriers thermal escape time from the quantum well. The calculation results show that with increas- ing of the ground-state energy level in quantum well, the tunneling probability increases and the tunneling time decreases, while the thermal escape time decreases because the ground-state energy level is shallower. Longitudinal optical phonon-assisted tunneling can be an effective method to solve the problem that both the tunneling time and the thermal escape time decrease simultaneously with the ground-state energy level increasing in quantum well.