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An echelle diffraction grating (de)multiplexer with arc-shaped grating teeth, based on a multi-guide vertical integration platform in InP is presented. The device can be applied to the 100GBASE-LR4 Ethernet systems, the crosstalk is better than −19 dB. By adjusting grating facets, the 3-dB spectral bandwidth is increased to 2.2 nm compared with 1.7 nm in a conventional design with a loss penalty less...
We propose a high efficient graphene-on-gap modulator (GOGM) by employing the hybrid plasmonic effect, whose modulation efficiency is ∼8-folds larger than that of present graphene-on-silicon modulator (GOSM) (∼0.1 dB / μm). The proposed modulator has the advantage of short modulation length ∼3.6 μm, relatively low insertion loss ∼0.32 dB and larger modulation bandwidth ∼0.48 THz. Moreover, an efficient...
Aiming at the problem of fault detection for satellite communication system, a prediction method based on Gaussian mixture model is proposed. Firstly, the observation sequence is collected by modem as well as frequency conversion equipment. Then feature parameters are extracted after pre-processing. The expectation maximum algorithm is applied to train the Gaussian mixture model. The posterior probabilities...
A holey fiber with round lattice is squeezed into a hotkey fiber with elliptical lattice and the results show that the squeezed fiber's birefringence is up to 10−2 in 1.5 ∼ 2.0μΜ wavelength range. Because of the 360 degree symmetry of the holey fiber with round lattice, it does not require deliberately to adjust the direction of extrusion when the fiber is squeezed. Thus the difficulty of fabricating...
A random phase-shifted fiber Bragg grating has been theoretically analysed by the transfer matrix method. Numerical predictions of the effects of phase-shifted points on the reflection spectra of such a grating are calculated. This fiber Bragg grating with 10 random phase-shifted points distributed has been fabricated. These predictions are compared with experimentally measured spectra of the random...
We propose a power efficient multiple access scheme for visible light communications (VLC) based on the block interleaved frequency division multiple access (B-IFDMA), which provides large frequency-diversity, flexible bandwidth allocation, low complexity of channel equalization and user separation. The impact of the number of subcarrier per block on the transmission performance under wireless optical...
A new method to modify excessively titled fiber gratings (Ex-TFGs) with 20 nm gold nanoparticles (GNPs) through 3-mercapt-otrimethoxysilane(MPTMS) was proposed. By monitoring the wavelength shift of Ex-TFGs for every modified step and using the scanning electron microscope (SEM), it proves that GN Ps are firmly combined on the surface of Ex-TFGs. Finally, by using different concentration of NaCl solutions...
We make some measurement research based on CW SPM method, and obtain the non-linear coefficient for the novel ultra low loss& large effective area single mode fiber. And we also discussed the measure uncertainty and non-linear coefficient influence factor.
ISAR imaging of high speed moving target has drawn extensive attention for its practical applications. However, the imaging quality is affected significantly by the phase modulation induced by high speed motion. To suppress the influences of high speed motion efficiently, a novel ISAR imaging method for high speed moving target based on the parametric sparse representation is proposed. First, the...
A methylcellulose (MC) coated humidity sensor by using photonic crystal fiber (PCF) based Mach-Zehnder interferometer (MZI) is proposed and experimentally demonstrated. It is fabricated by sandwiching a PCF between two standard single mode fibers (SMFs) with the air holes of the PCF in the fusion splicing region being fully collapsed. Experimental results show that this structure can not only carry...
With the development of passive optical networks (PONs), to cache videos on optical network units (ONUs) is now considering as an efficient scheme for better-quality video service provision. In this paper, we study the problem of collaborative video distribution among ONUs under the limited storage capacity of each ONU with the aim to maximize the video hit ratio of ONUs (VHRO). Two scenarios will...
A novel high SMSR dual-wavelength erbium-doped fiber laser operating in C-band is proposed and successfully demonstrated. Based on Arrayed-Waveguide Gratings (A WGs) as a comber filter and demultiplexer, the fiber laser retrieve the optical side-mode suppression ratio (SMSR) of 53dB and the output powers of-10.45dBm and-10.20dBm at the wavelengths 1554.87nm and 1555.65nm, respectively. The mode spacing...
Recently, some fiber sensing applications by coating graphene oxide or reduce graphene oxide have been proposed. In this paper, a novel humidity sensor based on core-offset fiber Mach-Zehnder interferometer coated graphene oxide film has been carried out. Here, we use the chemical method to deal with the surface of the fiber first, and then coated graphene oxide on the surface of the optical fiber...
We experimentally demonstrate a new method for modulating the light polarization state of the fiber. Both of the light polarization degree and polarization direction can be modulated. In the experiment, microfiber is immersed into the magnetic fluid (MF). When there is external magnetic field, magnetic nanoparticles of the MF generate magneto-optical dichroism and a non-circular symmetric distribution...
A MAC protocol for indoor VLC LAN based on CSMA/CA is described in the paper. Theoretically, the protocol can do well in solving HTP and terminal motion. We adopt RTS/CTS mechanism to avoid transmission collision among terminals. Also, an appropriate frame format based on IEEE 802.3 and IEEE 802.11 is proposed, contributing to solve HTP and terminal motion problem. At last, we established a demo system...
A simple and compact all-fiber sensor based on a sandwich fiber structure for simultaneous measurement of refractive index and temperature is proposed and demonstrated. The sensing element was made by cascading two core-offset attenuators with a fiber Bragg grating (FBG) in between. The two core-offset attenuators make up a Mach-Zehnder interferometer. The transmission spectrum would shift with the...
This paper proposes a two-dimension encryption orthogonal frequency division multiplexing passive optical network (OFDM-PON) based on dynamic chaos-iteration. The correlation monitoring method is adopted to achieve dynamic key distribution between OLT and ONUs. It is shown that key space can be larger than 1086, which would be against exhaustive attack effectively. We experimentally demonstrate a...
We propose a scheme of ultraviolet (UV) communication system, with polar channel coding method. The bit error rate (BER) performance of the UV polar code scheme is analyzed by simulations and offline experiments, in contrast with low-density parity-check (LDPC) scheme. Results suggest that the polar code scheme has a better BER performance than LDPC scheme in the UV communication system.
An equalization algorithm is proposed for carrier-less amplitude and phase (CAP) modulation system, which is regarded as a good candidate for short range optical communications, like electrical power optical fiber communication, optical access network. The constant module algorithm (CMA) combined with support vector machine (SVM) performs the equalization function. The simulation system was setup...
We propose a scheme for fast random number generation with a bandwidth-enhanced chaotic signal generated by injecting the signal of a traditional chaotic external-cavity semiconductor laser (ECSL) into a spectrum expansion module (SE). Our simulation results show that the bandwidth-enhanced chaotic can be generated and its efficient bandwidth can be greatly enhanced up to 70 GHz. Random bits in our...
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