Author Affiliations
Abstract
1 State Key Laboratory of Information Photonics and Optical Communications, Beijing University of Posts and Telecommunications, Beijing 100876, China
2 School of Digital Media and Design Arts, Beijing University of Posts and Telecommunications, Beijing 100876, China
Transverse mode characteristics of a laser are related to a variety of interesting applications. An on-demand mode solid laser in the 1064 nm band was proposed previously. In this paper, we provide a fiber laser for on-demand modes in the 1550 nm band to prescribe the pure and high-quality emission of a higher-order transverse laser mode, based on a simple construction with one spatial light modulator (SLM) and a single-mode erbium-doped fiber (SM-EDF). The SLM is designated to generate the desired higher-order mode and separate the higher-order mode and the fundamental mode. The fundamental mode oscillates in the fiber ring laser, and therefore the SM-EDF can be pumped with a single-mode 980 nm laser, no matter what higher-order mode is prescribed. In this proof-of-principle experiment, high-quality higher-order modes are observed from LP01 to LP105. Stable emission and real-time switching between modes can be easily realized by altering the phase on the SLM. In addition, the propagation of the LP01, LP11, LP21, and LP02 modes from the fiber laser is also demonstrated in a four-mode few-mode fiber.
Lasers, erbium Laser beam shaping Phase modulation Spatial light modulators Photonics Research
2017, 5(3): 03000256
Author Affiliations
Abstract
State Key Laboratory of Information Photonics and Optical Communications, Beijing University of Posts and Telecommunications, Beijing 100876, China
A stable and broadband microwave photonic phase shifter based on the combined use of a linear chirped fiber Bragg grating and optical single-sideband (OSSB) modulation is proposed and experimentally demonstrated. The quality of the radio frequency (RF) signal is improved by the spectral separation delay processing. The theoretical fundamentals of the scheme are explained and the phase shift can be controlled linearly by the wavelength of the light source. In the experiment, a full 360° phase shift with a 10 GHz bandwidth can be achieved and tuned dynamically, continuously, and stably.
060.3735 Fiber Bragg gratings 060.4510 Optical communications 060.5625 Radio frequency photonics Chinese Optics Letters
2016, 14(4): 040601
Author Affiliations
Abstract
State Key Laboratory of Information Photonics and Optical Communications, Beijing University of Posts and Telecommunications, Beijing 100876, China
In this paper, we present a mode-selective coupler based on a dual-core all-solid photonic bandgap fiber (AS-PBGF). Because they are all-solid, AS-PBGF-based mode converters are easier to splice to other fibers than those based on air-hole photonic crystal fibers. Mode conversions between the LP01 and LP11 modes, LP01 and LP21 modes, and LP01 and LP01 modes are obtained at the wavelength λ _ 1550 nm. The 3 dB wavelength bandwidth of these mode converters are 47.8, 20.3, and 20.3 nm, respectively.
Optical communications Optical communications Photonic crystal fibers Photonic crystal fibers Photonics Research
2015, 3(5): 05000220
Author Affiliations
Abstract
State Key Laboratory of Information Photonics and Optical Communications, Beijing University of Posts and Telecommunications, Beijing 100876, China
We demonstrate the theory of chromatic dispersion (CD)-induced constellation rotation (CR) in a radio-over-fiber (ROF) link and a method for compensation. We also propose a 60 GHz full-duplex ROF system with vector signal transmission including no CD effect. The evaluation of 5 Gb/s 16 quadrature amplitude modulation signal transmission shows that the CD-induced CR can be entirely overcome due to the proposed method which is simply implemented through an optical phase shifter. The proposed ROF schedule is not only applicable for V-band (57–64 GHz) but also fits for W-band (75–110 GHz), or any other bandwidth.
060.4510 Optical communications 060.5625 Radio frequency photonics Chinese Optics Letters
2015, 13(1): 010604
Author Affiliations
Abstract
State Key Laboratory of Information Photonics and Optical Communications, Beijing University of Posts and Telecommunications, Beijing 100876, China
The rapid growth of the Internet raises the importance of resource planning of Internet protocol (IP) over elastic optical networks (EONs), which is a challenging task due to more complex and obscure physical -constraints of it. Compared with network cost, the power consumption may eventually become the barrier to the expansion of the Internet. We present an energy-efficient virtual topology design (VTD) scheme for IP over EON. We explicitly explain and analyze the mixed integer linear programming model and the heuristic algorithm for this scheme. Numerical results show that the proposed VTD scheme can significantly save power consumption.
060.1155 All-optical networks 060.4251 Networks, assignment and routing algorithms 060.4256 Networks, network optimization Chinese Optics Letters
2014, 12(11): 110602
Author Affiliations
Abstract
By investigating the influence of the difference of refractive index between core and cladding (nco-ncl), normalized frequency (V ) and core radius (α) on both the intramodal and intermodal nonlinear coefficients (NCs) respectively, we design a novel weakly-coupled four-mode fiber with low nonlinearity. In general, under the premise of ensuring the low NCs between two non-degenerate modes, this design can reduce the intermodal NCs (< 0.5 W-1 \cdot km-1) between two degenerate modes and optimizes the parameters of differential group delays (DGDs) and chromatic dispersion. The optimized few mode fiber (FMF) is eligible for transmission and mode de-multiplexing in the receiver.
060.2280 Fiber design and fabrication 060.4230 Multiplexing 190.3270 Kerr effect Chinese Optics Letters
2014, 12(3): 030601
Author Affiliations
Abstract
A two-dimensional (2D) optical true-time delay (TTD) beam-forming system using a compact fiber grating prism (FGP) for a planar phased array antenna (PAA) is proposed. The optical beam-forming system mainly consists of a TTD unit based on the same compact FGP, one tunable laser for elevation beam steering, and a controlled wavelength converter for azimuth beam steering. A planar PAA using such 2D optical TTD unit has advantages such as compactness, low bandwidth requirement for tunable laser sources, and potential for large-scale system implementations. The proof-of-concept experiment results demonstrate the feasibility of the proposed scheme.
060.3735 Fiber Bragg gratings 060.4510 Optical communications Chinese Optics Letters
2013, 11(10): 100606
Author Affiliations
Abstract
With the emergence of high-bitrate applications, cross stratum optimization (CSO) attracts the interest of network operators because of its application in the joint optimization of optical networks and application stratum resources. Given the large-scale growth and high complexity of optical networks, achieving a more effective, accurate, and practical CSO becomes an important research focus. In this letter, we present a CSO-oriented, unified control architecture for OpenFlow-enabled triple-M optical networks. A novel dynamic global load balancing (DGLB) strategy with dynamic resource rating for CSO is presented based on the proposed architecture. The DGLB strategy is then compared with four other strategies by conducting experiments on a SOFT-based testbed with 1000 virtual nodes.
060.4510 Optical communications 060.4250 Networks 060.4254 Networks, combinatorial network design 060.4256 Networks, network optimization Chinese Optics Letters
2013, 11(7): 070605
Author Affiliations
Abstract
In flexible bandwidth optical networks, the dynamic lightpath setup and teardown inevitably lead to spectrum fragmentation which blocks the new connections. In order to effectively allocate the spectrum along a better route, a notion of available spectrum consecutiveness is introduced and three dynamic routing and spectrum assignment (RSA) algorithms are proposed in this letter accordingly. The novel algorithms retain the spectrum consecutiveness as much as possible when establishing a lightpath and reduce the spectrum fragmentation. Simulation results indicate that our proposed spectrum consecutiveness based RSA algorithms achieve lower blocking probability and higher adaptability to more line rates mixture.
060.4250 Networks 060.4264 Networks, wavelength assignment 060.4510 Optical communications Chinese Optics Letters
2012, 10(s1): S10606
Author Affiliations
Abstract
Key Laboratory of Information Photonics and Optical Communications, Ministry of Education, Beijing University of Posts and Telecommunications, Beijing 100876, China
Two novel dynamical quality of transmission (QoT) optimization schemes with explicit optimization targets and accurate end-to-end QoT estimation are proposed for reconfigurable transparent wavelength-division multiplexing (WDM) networks. Numerical simulations show that the scheme of quality (Q) best has the best Q factor improvement with large attenuation adjustment. The scheme of Q allowable can achieve minimized number of tuning sites and attenuation adjustment and also improve the Q factor of light path to the required value. In addition, the idea of dynamic QoT optimization and global impairment control has been experimentally demonstrated on a simple mesh network by the cooperation of a control plane and tunable devices.
传输质量优化 WDM网络 可调补偿器 060.1155 All-optical networks 060.2330 Fiber optics communications 060.4250 Networks 060.4256 Networks, network optimization Chinese Optics Letters
2010, 8(3): 270
