Simultaneous all-optical multi-channel RZ and CSRZ to NRZ format conversion

RZ-OOK to NRZ-OOK format conversion based on a single fiber Bragg grating

“…For instance, with the conversion between return-to-zero (RZ) and nonreturn-to-zero (NRZ) formats, the optical communication system will be more robust and more flexible for use in different networks such as optical time division multiplexing and wavelength division multiplexing networks [3,4] . The conversion from RZ to NRZ can be realized using various schemes [5][6][7][8][9][10][11] . Among the reported schemes, the spectrum-tailoring-based converter is allpassive and very attractive compared with time-domain waveform processing based on active operation device.…”

“…Among the reported schemes, the spectrum-tailoring-based converter is allpassive and very attractive compared with time-domain waveform processing based on active operation device. This is mainly owing to the advantages of the former such as the simplicity of the structure and stable performance [5][6][7][8][9][10][11] .…”

All-optical 40 Gbit/s data format conversion between RZ and NRZ using a fiber delay interferometer and a single SOA

“…If a 40 Gbit/s optical clock source is used, eye diagram and bit error rate (BER) of the format conversion can be measured. Since, on the one hand, comb spectrum of FDI is with periodic, multi-channel RZ to NRZ format conversions can be achieved [14], by cascading with a periodic filter, for example, a DWDM. On the other hand, in the SOA-FWM based NRZ to RZ format conversion, the generated conjugate wave and satellite wave both are converted RZ signal, so, two-channel NRZ to RZ format conversion can be realized [15].…”

“…Beating of the two co-propagating input waves inside the SOA generates refractive index and gain gratings at the frequency Ω = ω 2 -ω 1 . The input waves are scattered by these gratings which in turn leads to the creation of product waves, the conjugate wave and the satellite wave at optical frequencies ω3 and ω4, respectively, with ω 3 = ω 1 -Ω = 2ω 1 -ω 2 and ω 4 = ω 2 + Ω = 2ω 2 -ω 1 [14]. The conjugate wave just is the converted RZ signal.…”

Simultaneous RZ-OOK to NRZ-OOK and RZ-DPSK to NRZ-DPSK format conversion in a silicon microring resonator

“…In the past, significant efforts have been dedicated to on-off keying (OOK) RZ-to-NRZ conversion using nonlinear optical loop mirrors (NOLMs) [1], active injection locked lasers [2], or semiconductor optical amplifier (SOA) based devices [3,4] with relatively complex configurations. Single and multi-channel format conversions based on simple passive linear filter devices [5][6][7][8][9][10] have been demonstrated, however only applied to on-off keying modulation. On the other hand, because of its improved receiver sensitivity with balanced detection and superior transmission properties [11,12], differential phase shift keying (DPSK) has received special attention over the past decade.…”