Design of a comb generator for high capacity coherent-WDM systems

Transmission of a 1.12 Tb/s superchannel over 452 km fiber

“…The OSNR of this superchannel varied around 25 dB, i.e. within the acceptable range for this kind of bit rate and modulation scheme, as described in a previous work [8]. As already mentioned, initially we used the PRBS/MUX clock output as the OCG modulator RF source, provided its clock frequency is equal to the symbol rate of the electrical data signals.…”

A Survey of Optical Carrier Generation Techniques for Terabit Capacity Elastic Optical Networks

“…Gain competition and crosstalk also affects the flatness of the comb. Authors in [178], [179], [180], [181] provided a comprehensive theoretical and experimental analysis of RFS comb quality and stability in the presence of modulator and amplifier nonlinearities and investigated underlying factors for crosstalk. If the electric field of the input seed is denoted as E in (t) = E exp( j2π f 0 t), the RF drive voltages as f I = V pp sin(2π f m t) and f Q = V pp cos(2π f m t), the normalized transfer function of the RFS loop is given by [179]:…”

“…Sum Frequency Generation (SFG): SFG effect combines two photons at λ P and λ S to generate a third photon at λ SFG , where : [192], [195] 4 Comb enabled Terabit transmission [72], [181], [195], [196] 5 RFS Comb Stability and quality [178], [183], [191] 6 Crosstalk [179], [182] 7 Flatness [180], [183], [194] 8 Phase noise [184] 9 TNR and lines [185], [186], [187], [188], [190], [189] 10 Multi-frequency shifting [186], [187] 11 Dual loops [188], [193], [194] 12 complexity and cost [193], [194] 13 Noise Suppression [189], [190] From energy conservation perspective, one photon at frequency f P and one photon at frequency f S are annihilated by two photon absorption and the atom jumps to higher (virtual) energy level. Subsequently, a photon at f SFG = f P + f S is generated and the atom drops back to original state [199].…”

“…Transceiver and Network flexibility [66], [108], [53], [125], [39], [156], [203] 3 Comb enabled Terabit transmission [71], [72], [144], [170], [181], [195], [196], [225], [253] 4 Field trials [120], [121] VI. OFC DE-MULTIPLEXING/ FILTERING TECHNIQUES…”

Transmissão de um supercanal OFDM de 1,12 Tb/s por 452 km com eficiência espectral de 4 b/s/Hz

“…Neste artigo, apresenta-se o desenvolvimento experimental da transmissão por 452 km de um supercanal de 1,12 Tb/s, composto de 10 portadoras NGI-CO-OFDM (no-guard interval coherent OFDM). Na geração do supercanal foi utilizado um gerador comb com deslocador de frequência em anel [2,3]. As portadoras, separadas de 28 GHz, foram moduladas a uma taxa de 112 Gb/s no formato DP-QPSK (dual polarization, quadrature phase shift keying) e transmitidas por um anel de simulação de enlace óptico, constituído de seis amplificadores a fibra dopada por érbio, EDFA, e por cinco enlaces de fibra de sílica pura, quatro com 50 km e um com 26 km.…”