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A LDPC coded DAPPM (4×4 & 4×8) modulated scheme for both strong and weak turbulent free-space optical communication is proposed and its BER performance is analyzed by Monte Carlo simulation. Results prove its well reliability especially for weak turbulent channel, and calls for advanced forward error control means to deal with strong turbulent channel.
Compressive sensing (CS) is a novel technology to realize sub-Nyquist sampling for measuring of sparse signals. Due to the advantages of high bandwidth offered by photonics, realization of compressive sensing in a photonic link is of great interest. In this paper, we discussed the limitations of CS in a conventional photonic link A potential solution is proposed. To further reduce sampling rate, we...
We propose and experimentally demonstrate an all-optical on-line chromatic dispersion (CD) monitoring technique for 40 Gbit/s return-to-zero on-off-keying (RZ-OOK) signal using the four wave mixing (FWM) effect of semiconductor optical amplifier (SOA). The received signal, whose carrier frequency is suppressed by a fiber bragg grating (FBG), is launched into the SOA together with a continuous wave...
In this paper we study the maximum number of orthogonal azimuthal orbital angular momentum modes that can be supported by ring fibres while maintaining a radial single-mode profile. We demonstrate that a ring fibre within the standard communications fibre dimensions can support up to ± 52nd order OAM modes.
A compact arrayed waveguide grating triplexer based on small SU-8 strip waveguides is designed by using cross-order method. The AWG triplexer has a very compact size of as small as 1.3 × 0.402 mm2 since the high index contrast between SU-8 core layer and SiO2 and air cladding, and can be easily fabricated by using direct ultraviolet photolithography process without additional etching process. The...
An optical waveguide ring based notch filter was designed and fabricated with polymer PSQ-Ls for microwave photonic signal processing. The waveguide ring consists of a Mach-Zehnder interferometer (MZI) as the tunable coupler and two micro-heaters as the thermal-optic phase shifters. The coupling states, over-, critical- and under-coupling, were obtained with the phase shifter on the arm of MZI and...
In this paper, we experimentally demonstrated an optical generation of microwave carrier using optically injection-locked Fabry-Perot laser diodes in tandem through a phase modulator. It is verified that the proposed scheme is able to achieve an optical carrier suppressed (OCS) signal with a good suppression ratio simultaneously through a programmable optical filter and by use of optical injection...
Pressure/acoustic sensors based on a hollow-core photonic bandgap fiber (HC-PBF) with thin outer-cladding and a fiber-tip micro-cavity with ultra-thin graphene diaphragm are reported. The HC-PBF sensor demonstrates a normalized acoustic responsivity of~25 dB higher than standard single mode fiber while the fiber-tip sensor has a record high pressure responsivity of well over 1000 nm/kPa.
The optical attractive force can be available when the diameter of the tapered fiber is approaching the wavelength scale. By incorporating the tapered fiber into the micro fiber Mach-Zehnder and Sagnac loop interferometers, the optical attractive force can be employed to attract the desired micro- or nano-particles for active microsensing.
A special spun linear birefringent fiber was designed and achieved for the fiber optic current sensor (FOGS) based on polarization-rotated reflection interferometers. In contrast with conventional sensing fibers used in FOGS the fiber integrates a function of a quarter wave plate. A fiber optic current sensor based on the spun fiber was constructed, and its performance was tested. The sensor output...
An optical 90° hybrid based on Silicon-on-Insulator (SOI) 4×4 multimode interference(MMI) coupler is designed and simulated for the application of integrated coherent receiver(ICR). The beam propagation method(BPM) is used to verify the performance of the device. The 4×4 MMI coupler show good performance over C-band of TM mode with wavelength dependent loss(WDL) <0.3 dB, output power imbalance...
Silicon germanium (SiGe) is a completely miscible alloy with a lattice mismatch to the Si substrateof up to 4.17%, which has a lot of advantages, such as high refractive index, large electron mobility, compatibility with Si integrated circuit process, and so on. Based on the already established hundred nano-structure of SiGe ridge waveguide, effects of Ge content on effective refractive index and...
A novel class of tilt long-period fiber gratings (TLPFGs) coated with nano-scale gold film is introduced, which is at period of 368pm and easy to fabricate. Gold film at nano-scale has been deposited on TLPGs by adopting evaporation technique in Vacuum Film-Sputtering Machine. The experiment results demonstrate that the refractive index sensitivity measured by resonant wavelength shift is raised in...
Fibre Channel has been deployed on a number of military/aerospace platforms such as, F35/JSF, F8, F16, E2C, etc [1 2]. Owing to the incomparable performance of wavelength division multiplexing (WDM), advanced optical networks with WDM have been targeted as the technology of choice to realize the desired avionic network of the future [3–5]. The combination of FC with WDM is expected to play an important...
A novel dual wavelength semiconductor laser is proposed and experimentally demonstrated. Stable dual wavelength lasing is established by the grating structure consisting of two asymmetric phase-shifts, which are distributed along the phase-arranging regions (PARs) in the sampling pattern. The wavelength spacing is about 0.51nm corresponding to a beat signal about 64GHz.
A high-performance bi-reflection surface plasmon resonance waveguide sensor based on SiON was proposed. The thickness of Ag is optimized. The detection limit and the sensitivity are improved at the expense of loss using two planar reflection surfaces. A sensitivity of 103.8degree/RIU or 2.86×104dB/RIU as well as a refractive index variation of 1×10−5RIU were measured.
We report our recent progress on reconfigurable self-coupled optical waveguide (SCOW) resonators as optical filters. The SCOW resonators exhibit high-order optical filtering features with less strict requirement on device fabrication as required in regular coupled microring filters.
A carrier-depletion-based silicon MZ modulator is used for high-speed optical detection by leveraging the defect mediated absorption. As a modulator, the device exhibits a modulation efficiency of VπLπ=1.2 V.cm while as a detector, the responsivity is 22 mA/W at a reverse bias of-7.1 V. An operation speed of 35 Gb/s is obtained for both optical modulation and detection.
A monolithic integration of ten 1.5-μm range InGaAsP/InP distributed feedback lasers with 10×1 multimode-interference (MMI) optical combiner using the selective area growth technology is proposed and demonstrated. Our design of selectable light sources with selective area growth (SAG) technology can be fabricated easily, which is promising for obtaining low cost and high-yield multi-wavelength light...
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