All-Optical Modulation Format Conversion from QPSK to Symbol Rate Doubled BPSK Using FWM and Pulse Width Compression

Хэвлэлийн нэр: Journal of Lightwave Technology

Зохиогч:  Ш.Ганболд

Хамтран зохиогч:

Хэвлүүлсэн огноо: 2017-10-01

Хуудас дугаар: 4219-4226

Өгүүллийн хураангуй: Conversion between multi-level modulation formats is one of the key functions for flexible networking aimed at high spectral efficiency (SE) in optical fiber transmission. The authors previously proposed an all-optical conversion system from quadrature phase shift keying (QPSK) signal to simultaneous two binary phase shift keying (BPSK) signals by using four wave mixing (FWM) and interference. Since the converted BPSK signals are spatially separated, there is an issue that they cannot be transmitted at the same time through a single fiber core when 10 redirected to the same destination. In this paper, therefore, we consider to solve the issue by converting to a symbol rate doubled single BPSK signal using a pulse width compression technique. Numerical simulation reveals that the location of the pulse width compressor affects the system performances evaluated by bit error rate (BER) and constellation diagram. We have proposed a conversion method of optical modulation format from QPSK to BPSK using FWM, optical inference, and a CPF compressor. This method has an advantage of converting to a symbol rate doubled single BPSK signal, which is suitable for redirecting the signal to the same destination after conversion through a single fiber core. We have evaluated the performances of the proposed conversion system by BER and constellation diagrams. As a result of BER calculation, the proposed method shows 4-dB OSNR penalty to that of the B2B QPSK case. On the other hand, it shows  -4-dB OSNR penalty to that of the B2B QPSK with CPF compressor case. This is because of the phase recovery effect on the proposed conversion system. We have also compared the BER performance to an alternative configuration with two CPF compressors, resulted in 3-dB worse than the original configuration due to the disappeared phase recovery effect and severe nonlinear phase rotation. Experimental verification is one of our future works.

Өгүүллийн төрөл: Томсон-Ройтерсийн индекстэй(IF-JCR) сэтгүүл

Өгүүллийн зэрэглэл: Гадаад

Түлхүүр үг: #BPSK #four-wave mixing #modulation format

Өгүүлэл нэмсэн: Ш.Ганболд

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