The Infona portal uses cookies, i.e. strings of text saved by a browser on the user's device. The portal can access those files and use them to remember the user's data, such as their chosen settings (screen view, interface language, etc.), or their login data. By using the Infona portal the user accepts automatic saving and using this information for portal operation purposes. More information on the subject can be found in the Privacy Policy and Terms of Service. By closing this window the user confirms that they have read the information on cookie usage, and they accept the privacy policy and the way cookies are used by the portal. You can change the cookie settings in your browser.
As the differences in user business demand increasing, in order to effectively reduce the network delay and improve resource utilization, a High-priority Assignment First Dynamic Wavelength and Bandwidth Allocation algorithm (HAF-DWBA) in TWDM-PON is proposed. According to the Service-Level Agreement to determine the priority of ONUs, this algorithm can implement five types of T-CONT and four kinds...
Both channel and phase noise blind recover are proposed and demonstrated to recover the orthogonal-frequency-division-multiplexing (OFDM) signal without using any training symbols or pilot subcarriers in direct-detection optical OFDM. The proposed receivers can achieve similar performance compared to conventional OFDM receivers.
A design of mine wind velocity sensor is reported, which is based on differential pressure principle and adopts differential sensitive architecture composed of a bellows, an equal-strength beam and two fiber Bragg gratings(FBG). Furthermore, an algorithm is introduced for temperature compensation. Through these methods the cross sensitivity of temperature is effectively eliminated. The relation between...
In this paper, the long period fiber gratings (LPFGs) in standard SMF-28 telecommunication fibers without hydrogen loading were inscribed by using direct writing method of femtosecond laser pulses with pulse duration of 100 fs, repetition rate of 1kHz and a central wavelength of 800 nm. The transmission spectrum dependence on grating length was demonstrated experimentally. The loss peak of 1320 nm,...
In order to reduce the false matching rate and matching time, an improved algorithm based on RANSAC-SIFT was proposed. The feature points were extracted by SIFT algorithm firstly. Then most of the mismatching points were eliminated according to the constraints that matching distances tend to be consistent. Finally the remaining points were regarded as pre matching points for achieve fine matching...
In this paper, characteristics of high-order linearly chirped waveguide Bragg gratings (LCWBGs) are studied. The influence of saturation coefficient and grating order on the reflection spectrum (central wavelength, chirp coefficient, maximum reflectivity and total reflection bandwidth) of high-order LCWBGs is analyzed. LCWBGs with different grating orders have different optimal saturation coefficients...
We firstly demonstrate a low-bit DAC with a nonuniform quantification scheme in intensity modulated direct detection with filter bank based multicarrier (IMDD-FBMC) system for improving the signal-to-quantification noise ratio (SQNR). In this scheme, owing to the Gaussian-like distribution of FBMC signals, the low-level waveform occupies much more bits to mitigate the quantization noise hence improving...
An optical passband filter based on transmission liquid crystal technology is proposed and demonstrated. The bandwidth, wavelength and attenuation can be tuned by controlling the voltage applied on the liquid crystal chips. The insertion loss is <3dB, bandwidth tunable range is from 50GHz to 5000GHz, attenuation range is from 0 to 15dB. The filter can meet the technical requirements of CDCF ROADM.
In this paper, a method for detecting the photoelectric deviation of radar system based on tracking the Change 3 lander is presented. In this method, the accurate position of the lander is calibrated by using the relative position relationship between the Chang'e 3 lander and the feature points in the lunar surface image. Then the miss distance is obtained by calculating the relative position of the...
A microfluidic gas flowmeter based on optical fiber Fabry-Perot interferometer(FPI) was proposed and demonstrated. The sensor was formed by two embedded optical fibers with a microfluidic gas channel running across the two end faces. The gas flowrate was first tested by monitoring the shift of the resonancewavelength of the FPI. The intensity demodulation method was then applied to investigate thedynamic...
The performance of an integrated triple wavelength tunable filter based on the electro-optic effect in Lithium Niobate is proposed and analyzed. The filter contains four Bragg waveguide gratings, which separated by three waveguides and three pairs of electrodes. Three pairs of electrodes on both side of three waveguides is used to tune the phase shift caused by the waveguides. As a result, the wavelength...
In this paper, a high frequency vibration detection system of optical fiber sensing has been designed based on facet reflection principle, to satisfy the requirements of high frequency vibration measurement, including aerospace and fault diagnosis of high-speed rotating machinery, etc. The system modulates high frequency vibration signal by using the reflective intensity modulation fiber-optic sensor...
A system based on the Mach-Zehnder low-coherence interferometer for simultaneously measurement in the field of temperature and strain is presented. This system utilizes the principle of the optical path difference modulation and the coherence length modulation in the low coherence interferometer. After frequently testing the interference signal influenced by the temperature and the strain, the sensitivity...
The selection of virtualized network functions (VNFs) in service provisioning is a critical issue in inter-datacenter elastic optical networks. In this paper, considering load balancing of IT and spectrum resources, we propose two joint balancingfactors, i.e., Global Balancing factor (GB-factor) and Local Balancing factor (LB-factor) for VNFs selection. Then a Joint-Optimization Selection (JOS) algorithm...
A polarization converter (PC) based on the mode coupling in a hybrid plasmonic waveguide (HPW) is proposed. This PC comprises a Si core, a low index insulator layer surrounding the Si core, and two asymmetrically arranged Ag strips. Two orthogonal hybrid polarization modes are excited within the low index insulator layer. By exploiting the mode characteristics of these two hybrid polarization modes,...
We experimentally demonstrate the high speed DPSK modulation and demodulation for short reach optical communications by using a silicon microring modulator and a Sagnac interferometer at speed up to 30 Gb/s.
A power combining solution using magic-T is presented to apply in a shipborne X-band transmitter. According to scatter parameter theory, the factors that have influence on combining efficiency are analyzed; the combining efficiency and max output power are calculated. The results show that: (1) the magic-T has the advantage of small size, simple structure, good heat dissipation performance, so that...
Recently Time and Wavelength Division Multiplexed Passive Access Network (TWDM-PON) supporting 40Gb/s transmission rate becomes the main trend. If the ONU has some problems and cannot send data using the allocated bandwidth (i.e., ONU is failed), the bandwidth will be wasted. In this paper, we propose a Best Match Algorithm(BM) to reduce this waste. We put the traffic of ONUs into matching wavelength...
A peak-to-average power ratio (PAPR) reduction scheme based on the technique of the fast Hadamard transform (FHT) with repeated companding filtering (RCF)is proposed to reduce the PAPR in coherent optical orthogonal frequency division multiplexing (CO-OFDM). The simulations show that the novel scheme could achieve significant reduction in PAPR and a good bit error rate (BER) performance. At the CCDF=10...
In this paper, we reported an all-fiber burst-mode supercontinuum (SC) laser source which spanned from 0.8 to 3.2μm. The SC laser was generated within a 50-cm long Germania core fiber. The pump of the SC laser was an amplified nanosecond burst-mode laser pulse train at 1550 nm, which took pulse-pumping to suppress amplified spontaneous emission (ASE). In our experiment, the repetition rate of the...
Set the date range to filter the displayed results. You can set a starting date, ending date or both. You can enter the dates manually or choose them from the calendar.