  Transmitting polarization multiplexed carrier makes the receiver of a
coherent system local oscillator-less and frequency offset-free. A polarization
multiplexed carrier based self-homodyne (PMC-SH) system with an adaptive
polarization control (PC) can replace pulse amplitude modulation (PAM- 4) data
center interconnects. An adaptive PC technique is practically implemented by
using an electrically controlled PC along-with control circuitry for PMC-SH
systems. The de-multiplexing of the carrier and the modulated signal by using
this technique is validated through simulations for a 50 Gbaud PMC-SH
quadrature phase shift keying (QPSK) system with 20km standard single mode
fiber (SSMF). We successfully demonstrate 16 Gbaud PMC-SH systems with adaptive
PC for 10km SSMF channel. A bit error rate (BER) of 5.9 x 10^(-5) is achieved
with 32 Gb/s PMC-SHQPSK system without any signal processing while a BER of 8.7
x 10^(-3) is achieved with a 64 Gb/s PMC-SH quadrature amplitude modulation
(16QAM) system after equalization.
