Two-color quantum well infrared photodetector simultaneously working at 10-14 mu m

We have demonstrated a two-color quantum well infrared photodetector (QWIP) exhibiting simultaneous photoresponse with cutoff wavelengths at 11.8 and 14.5 mu m, respectively. Strong photocurrent signals are observed at temperature of 77 K. The simultaneous two-color photoresponse is achieved by utilizing a simple design by broadening the width of the quantum well and selecting an appropriate doping density. The two peaks are attributed to the intersubband transitions from the ground state to the first excited state (bound state) and to the fifth excited state (continuum state), respectively.

A Novel Geometric Algorithm for Blind Image Restoration Based on High-Dimensional Space

A novel geometric algorithm for blind image restoration is proposed in this paper, based on High-Dimensional Space Geometrical Informatics (HDSGI) theory. In this algorithm every image is considered as a point, and the location relationship of the points in high-dimensional space, i.e. the intrinsic relationship of images is analyzed. Then geometric technique of "blurring-blurring-deblurring" is adopted to get the deblurring images. Comparing with other existing algorithms like Wiener filter, super resolution image restoration etc., the experimental results show that the proposed algorithm could not only obtain better details of images but also reduces the computational complexity with less computing time. The novel algorithm probably shows a new direction for blind image restoration with promising perspective of applications.

模式识别中特征处理方法的应用研究

Submitted by 阎军 (yanj@red.semi.ac.cn) on 2010-04-07T05:09:46Z No. of bitstreams: 1 邓貌my dissertation【1019】.pdf: 857824 bytes, checksum: e7a2306ee9e05610846ff2a4b9552077 (MD5)

基于神经计算机的高速数据通道设计

Submitted by 阎军 (yanj@red.semi.ac.cn) on 2010-04-07T05:12:26Z No. of bitstreams: 1 刘蕾.pdf: 905512 bytes, checksum: 70a01dddda97f75dad960dd632bb30e0 (MD5)

基于仿生模式识别的玉米种子近红外光谱特征分析方法

Submitted by 阎军 (yanj@red.semi.ac.cn) on 2010-05-27T05:16:48Z No. of bitstreams: 1 基于仿生模式识别的玉米种子近红外光谱特征分析方法.pdf: 2528095 bytes, checksum: 9cc8ec32bc700eb2eb158ae05b9e2cc0 (MD5)

基于仿生模式识别的玉米种子品种真实性近红外光谱鉴定方法研究

Submitted by 阎军 (yanj@red.semi.ac.cn) on 2010-06-08T12:48:24Z No. of bitstreams: 1 郭婷婷 博士论文.pdf: 1273580 bytes, checksum: fcc8dc917681630d0932775b70620c4a (MD5)

基于高维仿生信息学的图像处理技术与应用研究

Submitted by 阎军 (yanj@red.semi.ac.cn) on 2010-06-08T13:02:00Z No. of bitstreams: 1 覃鸿--基于高维仿生信息学的图像处理技术与应用研究.pdf: 4519936 bytes, checksum: 94253c5ff17b15ad6a47113bd23f2a63 (MD5)

高维仿生信息处理技术及其应用研究

Submitted by 阎军 (yanj@red.semi.ac.cn) on 2010-06-08T13:04:00Z No. of bitstreams: 1 陈阳-高维仿生信息处理技术及其应用研究.pdf: 2578953 bytes, checksum: 10dbaebec4f162495bd31811d5a403c2 (MD5)

仿生人脸图像处理技术研究

Submitted by 阎军 (yanj@red.semi.ac.cn) on 2010-06-08T13:05:27Z No. of bitstreams: 1 金小贤-仿生人脸图像处理技术研究.pdf: 5146568 bytes, checksum: 320b614203905e5aa3bdbf5dfd8f43bf (MD5)

仿生模式识别算法研究及玉米品种鉴别应用

Submitted by 阎军 (yanj@red.semi.ac.cn) on 2010-06-08T13:09:35Z No. of bitstreams: 1 王徽蓉_博士论文.pdf: 1849738 bytes, checksum: bbf7aed6786fe32d4a3c297955de4ae1 (MD5)

Period Continuous Tuning of an Efficient Mid-Infrared Optical Parametric Oscillator Based on a Fan-out Periodically Poled MgO-Doped Lithium Niobate

We report a period continuously tunable, efficient, mid-infrared optical parametric oscillator (OPO) based on a fan-out periodically poled MgO-doped congruent lithium niobate (PPMgLN). The OPO is pumped by a Nd:YAG laser and a maximum idler output average power of 1.65 W at 3.93 mu m is obtained with a pump average power of 10.5 W, corresponding to the conversion efficiency of about 16% from the pump to the idler. The output spectral properties of the OPO with the fan-out crystal are analyzed. The OPO is continuously tuned over 3.78-4.58 mu m (idler) when fan-out periods are changed from 27.0 to 29.4 mu m. Compared with temperature tuning, fan-out period continuous tuning has faster tuning rate and wider tuning range.

12 W high efficiency single frequency ring laser

Single-frequency output power of 12 W at 1064 nm is demonstrated. Pumped by a fiber-coupled diode laser, the Nd:YVO4 produces 58.6% of the slope efficiency with respect to absorbed pump power, and 52.7% of the optical-optical efficiency and nearly diffraction-limited output with a beam quality parameter of M-2 approximate to 1.11. To the best of our knowledge, this is the highest slope efficiency and optical-optical efficiency in single-frequency Nd:YVO4 ring laser. The slope efficiency of the single frequency laser is close to the limit of the efficiency. [GRAPHICS] output spectrum of the single-frequency Nd:YVO4 ring laser

Complex networks constructed from irrational number sequences

In this paper, we construct (d, r) networks from sequences of different irrational numbers. In detail, segment an irrational number sequence of length M into groups of d digits which represent the nodes while two consecutive groups overlap by r digits (r = 0,1,...,d-1), and the undirected edges indicate the adjacency between two consecutive groups. (3, r) and (4, r) networks are respectively constructed from 14 different irrational numbers and their topological properties are examined. By observation, we find that network topologies change with different values of d, r and even sequence length M instead of the types of irrational numbers, although they share some similar features with traditional random graphs. We make a further investigation to explain these interesting phenomena and propose the identical-degree random graph model. The results presented in this paper provide some insight into distributions of irrational number digits that may help better understanding of the nature of irrational numbers.

A 20.1 W Solid-State Laser Pumped by 887 nm with High Efficiency and TEM00 Mode

High efficiency, TEM00 mode, high repetition rate laser pumped by 887 nm is reported. 20.1 W output laser emitting at 1064 nm is achieved in a 0.3 at % Nd-doped Nd:YVO4, which absorbs pumping light of 30.7 W at 887 nm. The opto-optic efficiency and the slope efficiency are 65.5 and 88.5%, respectively. The stable Q-switching operation worked well at 100 kHz and the beam quality is near diffraction-limit with M-2 factor measured as M-2 approximate to 1.2. And the pulse waveform is analyzed in this paper.

A New Discrimination Method of Maize Seed Varieties Based on Near-Infrared Spectroscopy

A new discrimination method for the maize seed varieties based on the near-infrared spectroscopy was proposed. The reflectance spectra of maize seeds were obtained by a FT-NIR spectrometer (12 000-4 000 cm(-1)). The original spectra data were preprocessed by first derivative method. Then the principal component analysis (PCA) was used to compress the spectra data. The principal components with the cumulate reliabilities more than 80% were used to build the discrimination models. The model was established by Psi-3 neuron based on biomimetic pattern recognition (BPR). Especially, the parameter of the covering index was proposed to assist to discriminating the variety of a seed sample. The authors tested the discrimination capability of the model through four groups of experiments. There were 10, 18, 26 and 34 varieties training the discrimination models in these experiments, respectively. Additionally, another seven maize varieties and nine wheat varieties were used to test the capability of the models to reject the varieties not participating in training the models. Each group of the experiment was repeated three times by selecting different training samples at random. The correct classification rates of the models in the four-group experiments were above 91. 8%. The correct rejection rates for the varieties not participating in training the models all attained above 95%. Furthermore, the performance of the discrimination models did not change obviously when using the different training samples. The results showed that this discrimination method can not only effectively recognize the maize seed varieties, but also reject the varieties not participating in training the model. It may be practical in the discrimination of maize seed varieties.