Optical Systems With High-Order DPSK and Star QAM Modulation Based on Interferometric Direct Detection

Extended Reach 10 Gb/s Transmission with an Optical I/Q Modulator Using VCSELs over OFDM-Based Multimode Fiber Link

“…The outputs of the interferometer are further processed with the help of adequate phase shifts. The interferometer helps in converting the phase difference information of two consecutive symbols into intensity information [14,15]. The delay of interferometer is adjusted to one-symbol duration.…”

Advanced optical modulation and format conversion

“…Seimetz et al [25] have investigated transmitters which require only binary electrical driving signals, using m consecutive PMods in serial configuration, where m is the number of bits per symbol. They have proposed and theoretically analyzed several possible structures of optical M-PSK and m-QAM using IQMods.…”

TDM-PON with 30 Gb/s D8PSK downstream and 10 Gb/s OOK upstream based on a digital incoherent receiver

“…In the receiver, the phase reference is provided by a delayed (by one symbol period) version of the signal. There are a number of options regarding D8PSK transmitters and receivers [8], depending on whether the complexity is placed in the optical or the electrical domain. In this paper, a parallel-serial configuration for the transmitter is used, where a nested pair of Mach-Zehnder (MZ) modulators creates a DQPSK signal and a phase modulator in series introduces a /4…”

“…Differential detection is usually implemented through a number of MZ delay interferometers (MZDIs) and balanced photo detectors (BPD) pairs, the number of which again depends on whether multilevel electrical signals are preferable [8]. In this paper, the approach that involves the minimum optical components is chosen, since the complexity of the ONU receiver should be as low as possible.…”