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1.
A new dual-frequency laser displacement measurement interferometer with nanometer precision has been developed. An eight-pass optical subdivision technology is proposed to improve resolution based on commercial interferometers. A static positioning error measuring method has been used to examine the precision and repeatability of the laser interferometer. An optical resolution of 1.24 nm and an accuracy of nanometer scale have been achieved.  相似文献   

2.
An optical cross connection network which adopts coarse wavelength division multiplexing (CWDM) and data packet is introduced. It can be used to realize communication between multi-CPU and multi-MEM in parallel computing system. It provides an effective way to upgrade the capability of parallel computer by combining optical wavelength division multiplexing (WDM) and data packet switching technology. CWDM used in network construction, optical cross connection (OXC) based on optical switch arrays, and data packet format used in network construction were analyzed. We have also done the optimizing analysis of the number of optical switches needed in different scales of network in this paper. The architecture of the optical interconnection for 8 wavelength channels and 128 bits parallel transmission has been researched. Finally, a parallel transmission system with 4 nodes, 8 channels per node, has been designed.  相似文献   

3.
In the field of optical computing and parallel information processing,several number systems have been used for different arithmetic and algebraic operations.Therefore an efficient conversion scheme from one number system to another is very important.Modified trinary number(MTN)has already taken a significant role towards carry and borrow free arithmetic operations.In this communication,we propose a tree-net architecture based all optical conversion scheme from binary number to its MTN form.Optical switch using nonlinear material(NLM)plays an important role.  相似文献   

4.
Calcium is one prospective element for the modern optical frequency standard.The 423-nm transition line of calcium atoms has been widely used in laser slowing and laser cooling,the precise spectrum measurement, and the magnetic optical trapping (MOT).However,there is no any available commercial diode laser working at this wavelength.We built a 423-nm laser based on extra bow-tie cavity and by using a Brewster- cut uncoated BIBO (BiB_3O_6) crystal,which worked at room temperature,with conversion efficiency of 3.75%,and a potential up to 20%.  相似文献   

5.
As a typical technology for optical encryption, phase retrieval algorithms have been widely used in optical information encryption and authentication systems. This paper presents three applications of two-dimensional(2D) phase retrieval for optical encryption and authentication: first, a hierarchical image encryption system, by which multiple images can be hidden into cascaded multiple phase masks; second, a multilevel image authentication system, which combines(t, n) threshold secret sharing(both t and n are positive integers, and t ≤ n) and phase retrieval, and provides both high-level and low-level authentication; and finally, a hierarchical multilevel authentication system that combines the secret sharing scheme based on basic vector operations and the phase retrieval, by which more certification images can be encoded into multiple cascaded phase masks of different hierarchical levels. These three phase retrieval algorithms can effectively illustrate phase-retrievalbased optical information security. The principles and features of each phase-retrieval-based optical security method are analyzed and discussed. It is hoped that this review will illustrate the current development of phase retrieval algorithms for optical information security and will also shed light on the future development of phase retrieval algorithms for optical information security.  相似文献   

6.
李海鸥  黄伟  邓泽华  邓小芳  刘纪美 《中国物理 B》2011,20(6):68502-068502
The fabrication and performance of 160-nm gate-length metamorphic AlInAs/GaInAs high electron mobility tran-sistors (mHEMTs) grown on GaAs substrate by metal organic chemical vapour deposition (MOCVD) are reported. By using a novel combined optical and e-beam photolithography technology, submicron mHEMTs devices have been achieved. The devices exhibit good DC and RF performance. The maximum current density was 817 mA/mm and the maximum transconductance was 828 mS/mm. The non-alloyed Ohmic contact resistance Rc was as low as 0.02 Ω- mm. The unity current gain cut-off frequency (fT) and the maximum oscillation frequency (fmax) were 146 GHz and 189 GHz, respectively. This device has the highest fT yet reported for a 160-nm gate-length HEMTs grown by MOCVD. The output conductance is 28.9 mS/mm, which results in a large voltage gain of 28.6. Also, an input capacitance to gate-drain feedback capacitance ratio, Cgs/Cgd, of 4.3 is obtained in the device.  相似文献   

7.
New development of atmospheric pressure plasma polishing   总被引:1,自引:0,他引:1  
Atmospheric pressure plasma polishing (APPP) high quMity optical surfaces. The changes of is a precision machining technology used for manufacturing surface modulus and hardness after machining prove the distinct improvement of surface mechanical properties. The demonstrated decrease of surface residual stresses testifies the removal of the former deformation layer. And the surface topographies under atomic force microscope (AFM) and scanning electron microscope (SEM) indicate obvious amelioration of the surface status, showing that the 0.926-nm average surface roughness has been achieved.  相似文献   

8.
In this paper,a novel method is proposed and employed to design a single diffractive optical element(DOE) for implementing spectrum-splitting and beam-concentration(SSBC) functions simultaneously.We develop an optimization algorithm,through which the SSBC DOE can be optimized within an arbitrary thickness range according to the limitations of modern photolithography technology.Theoretical simulation results reveal that the designed SSBC DOE has a high optical focusing efficiency.It is expected that the designed SSBC DOE should have practical applications in high-efficiency solar cell systems.  相似文献   

9.
The Er-doped concentric-cores dispersion compensating fiber (EDDCF) has been demonstrated. The rare earth has been doped as a ring around the inner core. We have obtained 14-dB gain at 1550 nm (using 100-mW pump power and 980-nm wavelength) with dispersion of about -165 ps/(km·nm). It is useful for the optical fiber network where amplification as well as negative dispersion are necessary.  相似文献   

10.
To exploit the parallelism of optics in data processing,a suitable number system and an efficient encod- ing/decoding scheme for handling the data are very essential.In the field of optical computing and parallel information processing,several number systems like binary,quaternary,octal,hexadecimal,etc.have been used for different arithmetic and algebraic operations.Here,we have proposed an all-optical conversion scheme from its binary to its other 2n radix based form with the help of terahertz optical asymmetric demultiplexer (TOAD) based tree-net architecture.  相似文献   

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