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1.
Phase-erased wavelength/format conversion and demodulation of 40 Gbit/s DPSK assisted by periodically poled lithium niobate 总被引:1,自引:0,他引:1
We report a novel phase-erased demodulation of differential phase-shift keying (DPSK) by exploiting cascaded second-harmonic
generation and difference-frequency generation (cSHG/DFG) in a periodically poled lithium niobate (PPLN) waveguide. Analytical
solutions are derived to clearly describe the operation principle. The binary optical phase information carried by the conventional
DPSK demodulation outputs is removed thanks to the cSHG/DFG in a PPLN waveguide. PPLN-assisted phase-erased wavelength conversion
and demodulation of 40 Gbit/s non-return-to-zero DPSK (NRZ-DPSK), return-to-zero DPSK (RZ-DPSK), and carrier-suppressed return-to-zero
DPSK (CSRZ-DPSK) are demonstrated in the experiment. Moreover, the accompanying all-optical format conversions from optical
duobinary (ODB) to NRZ and from ODB/alternate-mark inversion (AMI) to RZ are also substantiated in the experiment. In addition,
the calculated theoretical results including optical spectra, temporal waveforms, and phase diagrams also confirm the successful
implementation of PPLN-assisted 40 Gbit/s NRZ-DPSK/RZ-DPSK/CSRZ-DPSK phase-erased wavelength conversion, demodulation, and
ODB-to-NRZ and ODB/AMI-to-RZ format conversions. 相似文献
2.
We have experimentally verified a new idea for 40 Gbit/s wavelength conversion within the 1.5 microm band based on sum-frequency generation (SFG) in a periodically poled LiNbO3 waveguide. The spectrum and the temporal waveform of the output pump reveal that the input cw pump is converted to an optical pulse during SFG. Not only wavelength conversion but also a logic NOT gate at 40 Gbit/s are experimentally observed. 相似文献
3.
We propose and demonstrate all-optical multicasting logic XOR gate for non-return-to-zero differential phase-shift keying (NRZ-DPSK) signals by using non-degenerate four-wave mixing (FWM) in a highly nonlinear fiber (HNLF). Theoretical analysis regarding the operation principle of NRZ-DPSK logic XOR gate is clearly described by deriving an analytical solution under the non-depletion approximation. The NRZ-DPSK logic XOR operation is attributed to the linear relationship of complex amplitudes between converted idlers and input NRZ-DPSK signals. By using three non-degenerate FWM processes in an HNLF, 40 Gbit/s all-optical multicasting logic XOR gate for NRZ-DPSK signals are successfully demonstrated in the experiment. 相似文献
4.
The paper presents an alternative novel approach to obtain all-optical logic. We show that XOR, NOT, and AND logic could be
obtained by appropriately setting parameter of all-optical passive transistor. An AND gate followed by NOT gives NAND logic
(building block) that, in principle can provide complete set of passive, fiber compatible “self-trapped family” all-optical
logic gates (with Boolean completeness) and may find many possibilities in the area of all-optical computing. To give one
example, we propose all-optical half adder. 相似文献
5.
We demonstrate an all-optical reconfigurable logic gate based on dominant nonlinear polarization rotation accompanied with cross-gain modulation effect in a single semiconductor optical amplifier (SOA).Five logic functions,including NOT,OR,NOR,AND,and NAND,are realized using 10-Gb/s on-off keying signals with flexible wavelength tunability.The operation principle is explained in detail.By adjusting polarization controllers,multiple logic functions corresponding to different input polarization states are separately achieved using a single SOA with high flexibility. 相似文献
6.
155~Mb/s——10~Gb/s combined FSK-IM/optical label-packet modulation signals 100~km transmission over standard single mode fiber using mid-span spectral inversion by four-wave mixing in an SOA
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This paper introduces the mid-span spectral inversion by four-wave
mixing in a commercially available semiconductor optical amplifier
(SOA) with a length of about 1.5~mm to optical label switching
network based on combined frequency shift keying (FSK)-intensiy
modulation (IM)/optical label-packet modulation to overcome the
dispersion limitation of fiber. The 155~Mb/s--10~Gb/s combined
FSK/IM signal is experimentally transmitted over a 100~km standard
single mode fiber. 10-10 and 109 BER (bit error ratio),
or even better, is achieved for the FSK label and IM packet, respectively.
The -19~dB power conversion efficiency is obtained for -1~nm
wavelength detuning. 相似文献
7.
Yuan Fang Xiao Liu Xi Zheng Chunning Hou Wuliang Fang Bo Huang Xinying Li Shumin Zou Junwen Zhang Yufeng Shao Nan Chi 《中国光学快报(英文版)》2010,(9):906-908
Optical frequency shift keying (FSK) homodyne detection utilizing image rejection in FSK/amplitude shift keying (ASK) re-modulation wavelength-division-multiplexed passive optical network (WDM-PON) is proposed and demonstrated. Image rejection is adopted to achieve better performance. We show the result in back-to-back and 40-km distance respectively and apparent improvement is obtained in the latter situation by using image rejection. Several factors which affect the image rejection receiver are analyzed in order to find out the optimum parameters. Result shows that the presented scheme is suitable for super long reach access network, especially for future metro access network. 相似文献
8.
All-optical tunable wavelength conversion of ps-pulses is proposed and experimentally demonstrated by use of cascaded sum- and difference frequency generation (cSFG/DFG) in a periodically poled LiNbO3 (PPLN) waveguide. The amplified spontaneous emission (ASE) noise is effectively suppressed by employing two tunable filters. As a result, tunable wavelength down- and up-conversions are simultaneously observed. The temporal evolutions of the signal, pump, control and idler waves propagating along the PPLN waveguide are simulated. From the temporal waveforms and optical spectra in the simulations, it is interesting to find that continuous wave (CW) pump and control are evolved into optical pulses during the cSFG/DFG nonlinear interactions. Moreover, some new sidebands in the output pump spectrum are observed both in the simulations and experiments. 相似文献
9.
G. Schreiber H. Suche Y.L. Lee W. Grundkötter V. Quiring R. Ricken W. Sohler 《Applied physics. B, Lasers and optics》2001,73(5-6):501-504
Using an FM-mode-locked Ti:Er:LiNbO3 waveguide laser as the fundamental source, wavelength conversion by cascaded χ(2):χ(2)-difference frequency generation with a conversion efficiency of up to +3(-4.6) dB was demonstrated at a pulse repetition
rate of about 2 (10) GHz. In addition, multi-channel conversion was demonstrated with a fully packaged wavelength converter
using a continuous fundamental source.
Received: 29 May 2001 / Revised version: 10 August 2001 / Published online: 2 November 2001 相似文献
10.
A photonic approach for the generation of microwave hybrid frequency/phase shift keying (FSK/PSK) signal based on an integrated polarization division multiplexing dual-parallel Mach–Zehnder modulator (PDM-DPMZM) is proposed and demonstrated. In the scheme, the polarization modulator is employed to modulate the linearly polarized lightwave to generate an optical polarization-shift keying (PolSK) signal. Then the PolSK signal is sent to the PDM-DPMZM via a polarization controller to generate optical PSK signal. After photo-detection, a microwave hybrid FSK/PSK signal can be obtained. Simulations are conducted to verify the proposed scheme. As bit rate is set to 1 Gbit/s, a hybrid FSK/PSK signal with frequency of 10/15 GHz and phase shift of\(\pi\)is successfully demonstrated. Hybrid signals with 2-Git/s frequency shift and 1-Git/s phase shift are also implemented. The compression ratio of the generated signal is 25.5 and the main-to-sidelobe ratio is 11.2 dB. The generations of ASK, PSK and FSK signals are discussed, and the impact of the polarization extinction ratio is also analyzed. 相似文献
11.
R. Gutiérrez-Castrejón 《Optics Communications》2009,282(22):4345-4352
Two variations of the active Mach-Zehnder interferometer (MZI) that incorporate the recently proposed turbo-switch effect are introduced to carry out three key functionalities in forthcoming high-speed optical telecommunication networks, namely, all-optical wavelength conversion, photonic XOR gating and optical time-division demultiplexing. Their performance is numerically investigated at 160 Gb/s using a sophisticated semiconductor optical amplifier (SOA) model. The more practical of the two proposed geometries shows error-free operation as XOR Boolean gate, low patterning as wavelength converter, and poor performance as demultiplexer. For comparison, results derived from well-accepted (or typical) schemes are also presented, and the role of the required extra SOAs as distinguishing elements of the new architectures is investigated. 相似文献
12.
Minghao Li 《Optics Communications》2009,282(4):508-1260
We propose and numerically investigate a novel high-speed (40-Gb/s and above) optical frequency shift-keying (FSK) transmitter scheme. By optical carrier-suppressed modulation and differential phase-shift-keying (DPSK) to intensity modulation (IM) conversion, only one light source is needed in the proposed scheme to generate high-speed optical FSK signals. By using a Mach-Zehnder modulator (MZM) as phase modulator and an additional delay interferometer (DI) cascaded after the carrier-suppressed MZM to suppress the remaining carrier, the performance of our scheme can compete with the double-light-source counterparts. The transmission performances of the FSK signal generated with the proposed scheme as well as detuning and bandwidth tolerance of the demodulation filter are also carefully investigated. Simulation results show that the proposed FSK generation scheme is very suitable for the next-generation optical access network and optical label switching network. A potential application of our scheme in high-speed passive optical network is proposed. 相似文献
13.
The third harmonic of 810-nm 100-fs pulses at 130 μJ is generated very efficiently when ultrashort pulses from two noncollinear
beams interfere in an optical medium to create an instantaneous transient grating via the optical Kerr effect. The grating
couples two pathways for third-harmonic generation, each taking two photons from one beam and one photon from the other beam,
respectively. The coupling enables self-phase matching in the complete process, resulting in a conversion efficiency of ≈3%.
Scattering an independent beam at the transient grating confirms a lifetime limited by the pulse duration, with a reaction
on the order of one optical cycle. Using the second harmonic of a Ti-sapphire laser at 405 nm, it is shown that the generation
of the transient Kerr grating is a general feature, requiring less than 20 μJ/pulse. By introducing a third femtosecond beam
we are able to emulate various digital logic units with femtosecond response.
Received: 16 October 2001 / Published online: 6 June 2002 相似文献
14.
In this article, we propose the realization of XNOR logic function by using all-optical XOR and NOT logic gates. Initially, both XOR and NOT gates are designed, simulated and optimized for high contrast outputs. T-shaped waveguides are created on the photonic crystal platform to realize these logic gates. An extra input is used to perform the inversion operation in the NOT gate. Inputs in both the gates are applied with out of phase so as to have a destructive interference between them and produce negligible intensity for logic ‘0'. The XOR and NOT gates are simulated using Finite Difference Time Domain method which results with a high contrast ratio of 55.23?dB and 54.83?dB, respectively at a response time of 0.136?ps and 0.1256?ps. Later, both the gates are cascaded by superimposing the output branch of the waveguide of XOR gate with the input branch of the waveguide of NOT gate so that it can be resulted with compact size for XNOR logic function. The resultant structure of XNOR logic came out with the contrast ratio of 12.27?dB at a response time of 0.1588?ps. Finally, it can be concluded that the proposed structures with fair output performance can suitably be applied in the design of photonic integrated circuits for high speed computing and telecommunication systems. 相似文献
15.
Shiming Gao Changxi Yang Xiaosheng Xiao Yu Tian Zheng You Guofan Jin 《Optics Communications》2006,266(1):296-301
We investigate bandwidth enhancement and response flattening of wavelength conversion based on cascaded sum-frequency generation and difference-frequency generation (SFG/DFG) in quasi-phase-matched periodically poled lithium niobate waveguides by use of two pump lights. Analysis shows that the conversion properties deeply depend on the pump settings. The bandwidth is efficiently enhanced by augmenting the pump wavelength difference. The critical bandwidth corresponding to the response fluctuation of 1 dB in a 3-cm-long waveguide reaches 80-90 nm, which is enough to cover the entire conventional-band and long-wavelength-band. The cascaded SFG/DFG bandwidth is about 24% broader than that of the cascaded second-harmonic generation and difference-frequency generation-based configuration with the same waveguide length. However, the response fluctuation is also enhanced together with the bandwidth enhancement. The method of pump detuning is presented to flatten the response fluctuation. The fluctuation is reduced by more than 1 dB and it can be further reduced by increasing the pump detuning value with a little efficiency penalty. 相似文献
16.
Jing Li 《Optics Communications》2007,277(1):114-117
In the paper, a new way of intracavity frequency-tripled all-solid-state laser to generate continuous wave blue coherent radiation is firstly demonstrated. High-efficiency of continuous wave third harmonic generation using the approach of double-resonance at fundamental frequency and second harmonic is developed by insertion of one wedge prism for the phase control. The maximum output power at the wavelength of 447 nm, which was generated with two long LiB3O4 crystals by noncritical phase matching, is about 1.15 W with a beam quality factor of M2 of 1.05. From the experimental results, the generation of continuous wave blue light using this way with higher conversion efficiency can be achieved. 相似文献
17.
U. Heitmann M. Kötteritzsch S. Heitz A. Hese 《Applied physics. B, Lasers and optics》1992,55(5):419-423
Design and performance characteristics of a tunable dye laser system for sum frequency mixing (SFM) in a BBO crystal are presented. The system is composed of two tunable pulsed dye lasers pumped synchronously by the second harmonic of a commercial Nd:YAG laser. The radiation produced by the first dye laser is frequency doubled by second-harmonic generation (SHG) in KDP and subsequently mixed by SFM in BBO with the light of the second dye laser. The interest was focussed on generation of tunable laser radiation below 205 nm with high output power and long-time wavelength stability. High conversion efficiencies enable output energies of 100 J (20 kW) at 196 nm using only moderate Nd:YAG pump energies of 67 mJ. Altogether, a laser system with very good specifications for analytical application in the near VUV spectral region is reported. 相似文献
18.
We report, for the first time, an efficient intra-cavity second-harmonic generation (SHG) at 1084 nm in a nonlinear optical crystal, BiB3O6(BIBO) at the direction of (θ, ?) = (170.1°, 90°), performed with a LD end-pumped cw Nd:YVO4 laser. With 590 mW diode pump power, a continuous-wave (cw) SHG output power of 19 mW at 542 nm yellow-green color has been obtained using a 1.5 mm-thick BIBO crystal. The optical conversion efficiency was 3.22%. It was found that the output wavelength could be 532 nm, 537 nm or 542 nm according to regulating the angle of BIBO. 相似文献
19.
Simultaneous wavelength conversion based on four-wave mixing (FWM) for 10-Gb/s NRZ payload and 2.5-Gb/s OFDM label signals in optical switching network is experimentally demonstrated. The dual-pump scheme based on FWM in semiconductor optical amplifier (SOA) is employed and simultaneous wavelength conversion for optical packet with one optical payload of 10-Gb/s non-return-to-zero (NRZ) on-off keying (OOK) signals and one optical label of 2.5-Gb/s OFDM signals are realized. The bit-error-rate performance is evaluated for both payload and label after wavelength conversion. 相似文献
20.
O. Prakash H.-H. Lim B.-J. Kim K. Pandiyan M. Cha B. K. Rhee 《Applied physics. B, Lasers and optics》2008,92(4):535-541
Collinear broadband optical parametric generation (OPG) using periodically poled lithium niobate (PPLN) crystals were designed
and experimentally demonstrated with the quasi-phase matching (QPM) periods of 21.5, 24.0, and 27.0 μm. The broad gain bandwidth was accomplished by choosing a specific set of the period and the pump wavelength that allows
the group velocities of the signal and the idler to match close to the degeneracy point. OPG gain bandwidth and also the spectral
region could be controlled by proper design of QPM period and pump wavelength. The total OPG gain bandwidth of 600, 900, and
1200 nm was observed for the PPLN devices with QPM periods of 21.5, 24.0, and 27.0 μm, respectively. We have also observed multiple color visible generation whenever the OPG spectrum was significantly broad.
From the visible peaks of the three PPLN samples, it is found that broad gain bandwidth is crucial in the temperature-insensitive
collinear simultaneous RGB generation from a single crystal. 相似文献