Shenzhen Key Laboratory of Micro Nano Photonic Information Technology

Shenzhen, China

Shenzhen Key Laboratory of Micro Nano Photonic Information Technology

Shenzhen, China

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Wang Y.,Shenzhen University | Zhang D.,Shenzhen University | Xu S.,Shenzhen University | Xu S.,Shenzhen Key Laboratory of Micro Nano Photonic Information Technology | And 3 more authors.
Microwave and Optical Technology Letters | Year: 2017

We report numerical and experimental investigations of the large band gap in a newly designed two-dimensional square lattice photonic crystals (PCs) that is formed by distributing cylindrical Al2O3 pillars array in contact with air. The band gap of TE mode for the PCs is calculated by plane wave expansion method. The numerical results show that there is a lenient photonic band gap (PBG), which is expressed as normalized frequency range 0.3525–0.4687. To validate the numerical result, we perform the experiments in the microwave regime using an Agilent E8361C vector network analyzer. The measured reflection and transmission characteristics of the PCs sample have shown a large band gap between 8.62 and 11.554 GHz (relative bandwidth is 29.34%), which is corresponding perfectly with the numerical results. At the central frequency of 10 GHz, the isolation of PBG reaches −57.24 dB and about 90% energy is reflected back to the input port. © 2017 Wiley Periodicals, Inc. Microwave Opt Technol Lett 59:1347–1350, 2017. © 2017 Wiley Periodicals, Inc.


Zheng G.,Shenzhen University | Zheng G.,Shenzhen Key Laboratory of Micro Nano Photonic Information Technology | Deng X.,Shenzhen University | Deng X.,Shenzhen Key Laboratory of Micro Nano Photonic Information Technology | And 4 more authors.
Applied Optics | Year: 2017

This paper investigates theoretically and numerically the propagation characteristics of a circular Airy beam (CAB) in a uniaxial crystal in detail. The beam loses its boundary cylindrical symmetry during propagation because of the medium anisotropy, although it propagates along the optical axis. This effect of anisotropy on the propagating beam becomes increasingly evident with the increase of the propagation distance. Another main influential factor of the propagation characteristics is the ratio of the extraordinary refractive index to the ordinary refractive index (ne/no). The more the value deviates from 1, the worse the symmetry of the beam intensity distribution becomes. The polarization becomes notably complicated, but possesses a vortex state with a topological charge of 2 during propagation. The abruptly autofocusing characteristic, the most important property of CABs, also appears when the crystal length is long enough, which is greatly different from that characteristic in isotropic media. This work is helpful for the design of optical devices based on uniaxial crystals for beams with some special wavefronts. © 2017 Optical Society of America.


Zheng G.,Shenzhen University | Zheng G.,Shenzhen Key Laboratory of Micro Nano Photonic Information Technology | She W.,Sun Yat Sen University | Ouyang Z.,Shenzhen University | Ouyang Z.,Shenzhen Key Laboratory of Micro Nano Photonic Information Technology
Applied Physics B: Lasers and Optics | Year: 2010

"Quasi-phase matching" is first introduced to the optical activity (OA) effect and a wave coupling theory for the quasi-phase-matched (QPM) OA effect in periodically poled "gyroelectric" crystals is developed. The OA effect is observed clearly even though the propagating direction of light deviates far from the optical axis in the QPM crystal with both optical activity and natural birefringence. The QPM OA effect provides a special way to determine the gyration coefficients that cannot be observed by the normal OA effect, and it provides a principle for building optical filters without external field. © 2009 Springer-Verlag.


Tao K.,Shenzhen University | Tao K.,Shenzhen Key Laboratory of Micro Nano Photonic Information Technology | Tao K.,University of Colorado at Boulder | Xiao J.-J.,Harbin Institute of Technology | Yin X.,University of Colorado at Boulder
Applied Physics Letters | Year: 2014

We present a versatile add-drop integrated photonic filter (ADF) consisting of nonreciprocal waveguides in which the propagation of light is restricted in one predetermined direction. With the bus and add/drop waveguides symmetrically coupled through a cavity, the four-port device allows each individual port to add and/or drop a signal of the same frequency. The scheme is general and we demonstrate the nonreciprocal ADF with magneto-optical photonic crystals. The filter is immune to waveguide defects, allowing straightforward implementation of multi-channel ADFs by cascading the four-port designs. The results should find applications in wavelength-division multiplexing and related integrated photonic techniques. © 2014 AIP Publishing LLC.


Tao K.,Shenzhen University | Tao K.,Shenzhen Key Laboratory of Micro Nano Photonic Information Technology
Physica Status Solidi - Rapid Research Letters | Year: 2013

A resonance splitting effect is investigated in a system composed of two cavities coupled by two unidirectional waveguides. Both theoretical analysis and numerical calculations demonstrate that the resonance splitting (indicating a coupling between the cavities) is independent of the phase shift between the cavities, which is in contrast to previous research where reciprocal waveguides are used. Moreover, this splitting can be tunable by an external magnetic field. Our findings offer a possibility to realize effective coupling between remote on-chip resonators, which is highly demanded in the next-generation photonic circuits. © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.


Wang Y.,Shenzhen University | Zhang D.,Shenzhen University | Xu S.,Shenzhen Key Laboratory of Micro Nano Photonic Information Technology | Ouyang Z.,Shenzhen University | And 2 more authors.
Optics Communications | Year: 2016

A new defect structure of two-dimensional magnetic-photonic crystal is given and a new three-port Y-junction circulator using a ferrite cylinder is proposed in this short paper. Based on the agreements between the resonance frequency of micro-cavity constructed by a point defect in the 2D triangular lattice photonic crystal with those numerical results of corresponding literatures, external characteristics of the circulator were calculated by the plane wave expansion method and finite element method. According to the scaling theory of Maxwell's equations, a 3 cm Y-junction 2D MPCs circulator is developed by scaling the radius of the center ferrite cylinder. The results show that there is a significant improvement for insertion loss 0.062 dB and isolation 26.2 dB compared with those in literatures. © 2016 Elsevier B.V. All rights reserved.


Wu C.J.,Shenzhen University | Wu C.J.,Yuan Ze University | Liu C.P.,Yuan Ze University | Ouyang Z.,Shenzhen University | Ouyang Z.,Shenzhen Key Laboratory of Micro Nano Photonic Information Technology
Applied Optics | Year: 2012

An optical logic NOT gate (OLNG) is presented based on photonic crystal (PhC) waveguides without nonlinear materials and optical amplifiers. Also, a way of determining the operating parameters is presented. It is demonstrated through finite-difference time-domain simulations that the structure presented can operate as an OLNG. The optimized contrast ratio, defined as the logic-"1" output power divided by the logic-"0" output power, is found to be 297.07 or 24.73 dB. The size of the OLNG can be as small as 7a × 7a, where a is the lattice constant of the PhC. Further, the OLNG presented in this paper can operate at a bit rate as high as 2.155 Tbit?s, which is much higher than that of electronic or optical logic gates developed until now. Moreover, as it is not based on the nonlinear effect, the OLNG can operate at very low powers and a relatively large operating bandwidth. This is favorable for large-scale optical integration and for developing multiwavelength parallel-processing optical logic systems. © 2012 Optical Society of America.


Huo J.-C.,Shenzhen Key Laboratory of Micro nano Photonic Information Technology | Wu Q.-Y.,Shenzhen Key Laboratory of Micro nano Photonic Information Technology | Zeng X.-J.,Shenzhen Key Laboratory of Micro nano Photonic Information Technology | Deng L.,Shenzhen Luohu Hospital
Guangdian Gongcheng/Opto-Electronic Engineering | Year: 2012

A three-dimensional (3-D) shape measurement method using partial coding structured light is proposed. This method combines the conventional phase unwrapping technique with partial coding technique, which not only effectively reduces the number of projected and captured images but also enhances the reliability of phase unwrapping. First, several adjacent stripes are integrated by partial coding technique to reduce the density of stripes, and then a conventional phase unwrapping algorithm is applied to obtain the absolute phase of the entire image with integrated stripes. Experimental results show that this method can greatly reduce the number of images which are needed for reconstruction, and it has a good accuracy and reliability.


Liu C.,Shenzhen University | Liu C.,Shenzhen Key Laboratory of Micro Nano Photonic Information Technology | Li S.,Shenzhen University | Li S.,Shenzhen Key Laboratory of Micro Nano Photonic Information Technology | And 2 more authors.
Shenzhen Daxue Xuebao (Ligong Ban)/Journal of Shenzhen University Science and Engineering | Year: 2013

A shutter pulse generator was designed, which is based on the metal oxide semiconductor field effect transistor (MOSFET). By using the N-channel level shifter for driving switch groups, which consist of Series MOSFETs and controlled by programmable logic device FPGA (field programmable gate array), a high-voltage pulse is achieved with high-speed front edge and back edge, after processing by pulse forming circuit. Experimental results showed that with a load of 1.1 μF the amplitude of pulse is 800 V and the width of pulse is 81 μs, both its front edge and back edge lasted less than 1 μs. The system is anti-jamming and reliable.


Tao K.,Shenzhen University | Tao K.,Shenzhen Key Laboratory of Micro Nano Photonic Information Technology
Advanced Materials Research | Year: 2012

Based on coordinate transformation, we extend the theory of unidirectional surface mode at a plane interface to a more general case of arbitrary boundary. We provide direct simulations to prove the validity of extension. Because it depends only on the signs of off-diagonal elements in the tensor of permittivity (for TM mode) or permeability (for TE mode), the unidirectionality is robust in a wide range of frequency. Moreover, this kind of surface mode is fairly robust with smoothly changing surface. These properties are very useful to design compact nonreciprocal component with wide range of operating frequency in various cases, such as broadband isolators and circulators. © (2012) Trans Tech Publications.

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