PROJECT TITLE :

Phase Regeneration of a BPSK Data Signal Using a Lithium Niobate Phase Modulator

ABSTRACT:

We propose a theme for phase regeneration of an optical binary part shift keying (BPSK) knowledge signal employing a Lithium Niobate (LiNbO3) phase modulator. The scheme relies on heterodyne detection of the BPSK information signal with a continual wave native oscillator (CW-LO). Carrier recovery is then achieved in the electrical domain employing a ×a pair of frequency-multiplier and a narrow-band filtering scheme. Subsequently, a superposition of the recovered carrier and the heterodyne detected knowledge signal is used to modulate the CW-LO during a LiNbO3 part modulator. The result is a parametric mixing process in the optical domain, leading to a phase-regenerated BPSK information signal by the coherent superposition with a phase-inverted copy. The proposed theme constitutes a compact and stable setup, where active part-stabilization of the electrical data- and carrier-methods will probably be avoided. An analytical derivation of the operating principle is provided, using Jacobi–Anger expansions to describe the phase-modulation. A proof-of-principle experiment is carried out, demonstrating regeneration of a ten Gb/s NRZ-BPSK knowledge signal degraded by a five-GHz sinusoidal section-noise tone. Within the proof-of-principle demonstration, the decorrelated knowledge- and LO-carriers are derived from the same CW supply. A preliminary check with separate CW sources for information and LO, but while not the desired electrical slender-band carrier filtering, is also included. Finally, numerical simulations of the regenerator performance in the presence of wideband section- and amplitude-noise are performed.