High-speed optical DQPSK and FSK modulation using integrated Mach-Zehnder interferometers

Abstract

We investigated an integrated optical modulator consisting of two Mach-Zehnder interferometers. The modulator can generate optical signals in various types of modulation formats, which have advantages for long-haul transmission, optical labeling, etc. By using a fabricated versatile optical modulator having traveling-wave electrodes designed for high-speed signals, we demonstrated generation of optical 40Gb/s frequency-shift-keying signals, which can be demodulated by an optical filter. 80Gb/s optical differential quadrature-shift-keying modulation was also demonstrated, where 40Gb/s in-phase and quadrature data were, simultaneously, fed to the modulator.

109-Tb/s (7×97×172-Gb/s SDM/WDM/PDM) QPSK transmission through 16.8-km homogeneous multi-core fiber

“…The light source used for the measurement channel was a narrow-linewidth (about 100 kHz) tunable laser while the other sources were DFB lasers. The odd and even carriers were separately modulated in respective parallel dual-drive Mach-Zehnder modulators to generate 86-Gb/s QPSK signals [11]. Modulators for even channels were driven by two complementally 43-Gb/s 2 11 -1 pseudorandom bit sequence (PRBS) non-return-to-zero (NRZ) electrical signals in a push-pull mode, while modulators for odd channels were driven by complementally 43-Gb/s 2 9 -1 PRBS NRZ signals.…”

Photonic Millimeter-Wave Generation and Distribution Techniques for Millimeter/Sub-Millimeter Wave Radio Interferometer Telescope

“…In the high-extinction ratio lithium niobate (LiNbO 3 ) Mach-Zehnder intensity modulator (Izutsu et al (1977), Izutsu et al (1981), Kawanishi et al (2006), Kawanishi et al (2004a), Kawanishi et al (2004b), Kawanishi et al (2007), Onillon et al (2005), Vegas et al (2003)), the optical frequency difference between two optical signals is exactly twice (or four times) the modulation frequency, and the output signal is equivalent to FSK (frequency shift keying) spectrum. Compared to the optical phase lock scheme, the Mach-Zehnder modulator (shown in Fig.…”

16 QAM synthesis by angular superposition of polarization using dual-polarization QPSK modulator

“…Multilevel optical modulation formats are good candidate for high spectral efficiency transmission. Many modulation formats have been investigated; for example, differential quadrature phase-shift-keying (DQPSK) 1 , quadrature phase-shift-keying (QPSK) with coherent detection schemes, quadrature amplitude modulation (QAM) 2 , and so on. DQPSK using a dual parallel Mach-Zehnder modulator (DPMZM) is highly attractive because of its practicality, where in-phase (I) and quadrature (Q) components of a carrier light are independently modulated by using the modulator 1 .…”