Author Affiliations
Abstract
1 Optical Communications Research Group, Northumbria University, NE1 8ST, UK
2 Siemens AG, Corporate Technology, Erlangen CT T DE HW3, Germany
3 Department of Electronic & Electrical Engineering, University College London, WC1E 7JE, UK
4 Department of Engineering Science, University of Oxford, OX1 3PJ, UK
This paper presents an experimental demonstration of a visible light communications link with an light emitting diode and a low-bandwidth organic photodetector as transmitter and receiver, respectively, that achieves sub 4 Mbits/s speeds. An artificial neural network (ANN) equalizer is required in order to achieve such high data rates because of the influence of intersymbol interference. The digital modulation formats tested in this paper are nonreturn-to-zero on–off keying (OOK), and fourth-order pulse position modulation (4-PPM). Without equalization, data rates of 200 and 300 kbits/s can be achieved for 4-PPM and OOK, respectively. With ANN equalization, data rates of 2.8 and 3.75 Mbits/s can be achieved for the first time for OOK and 4-PPM, respectively.
Optical communications Polymer active devices Photonics Research
2013, 1(2): 02000065
Author Affiliations
Abstract
Key Laboratory of Luminescence and Optical Information, Ministry of Education, Institute of Opto-Electronic Technology, Beijing Jiaotong University, Beijing 100044, China
We fabricate an ultraviolet photodetector based on a blend of poly (N-vinylcarbazole) (PVK) and 2-tert-butylphenyl-5-biphenyl-1,3, 4-oxadiazole (PBD) using spin coating. The device exhibites a low dark current density of 2.2 \times 10?3 \muA/cm2 at zero bias. The spectral response of the device shows a narrow bandpass characteristic from 300 to 355 nm, and the peak response is 18.6 mA/W located at 334 nm with a bias of –1 V. We also study the performances of photodetectors with different blend layer thicknesses. The largest photocurrent density is obtained with a blend of 90 nm at the same voltage.
有机光电探测器 紫外 带通 PVK 250.0040 Detectors 250.2080 Polymer active devices 310.1860 Deposition and fabrication 310.6845 Thin film devices and applications Chinese Optics Letters
2011, 9(5): 052501
Author Affiliations
Abstract
Photonic Manufacturing Science and Technology Center and School of Materials Science and Engineering, Jiangsu University, Zhenjiang 212013
Two-photon photopolymerization (TPP) with femtosecond laser is a promising method to fabricate three-dimensional (3D) photonic crystals (PCs). Based on the TPP principle, the micro-fabrication system has been built. The 3D woodpile PCs with rod space of 2000 nm are fabricated easily and different defects are introduced in order to form the cross-waveguide and the micro-laser structure PCs. Simulation results of the optical field intensity distributions using finite-difference time domain (FDTD) method are given, which support the designs and implementation of the PC of two types in theory.
飞秒激光 光子晶体 微加工 双光子 光聚合 320.7110 Ultrafast nonlinear optics 060.4510 Optical communications 250.2080 Polymer active devices 250.5300 Photonic integrated circuits Chinese Optics Letters
2009, 7(2): 02165
Author Affiliations
Abstract
Photonics Fabrication Science Center, Jiangsu University, Zhenjiang 212013
Great efforts has been made on fabricating photonic crystals (PCs) with photonic band gaps (PBGs) during the past decade. Three-dimensional (3D) log pile PC was fabricated fast by direct femtosecond laser writing in ORMOCER. Qualitative analysis of the errors of PC was investigated using the Image Pro Plus. Surface qualities such as bending, distortion, and surface roughness were shown, and the band gap in the infrared wavelength region was observed. Meanwhile, the theory was experimentally verified that the center of PBG diminishes as the crystal lattice period reduces. Therefore, it is possible to fabricate PCs whose band gap range is from the near-infrared to visible wave band.
飞秒激光 光子带隙 光子晶体 双光子 060.4510 Optical communications 250.2080 Polymer active devices 250.5300 Photonic integrated circuits Chinese Optics Letters
2008, 6(11): 864
