'Institute of Electrical and Electronics Engineers (IEEE)'
Doi
Abstract
Segmenting a silicon modulator can substantially increase its electro-optic bandwidth without sacrificing modulation
efficiency. We demonstrate a segmented silicon IQ modulator
and experimentally explore both modulator design and operating
point to optimize systems trade-offs in coherent detection. An
electro–optic bandwidth of greater than 40 GHz is measured for
a 4-mm-long segment, and greater than 60 GHz for a 2-mmlong segment. We evaluate optical transmission experimentally
at 120 Gbaud for 16-ary quadrature amplitude modulation
(QAM) and 32QAM. The segments are operated in tandem with
identical data at each segment. We present an experimental
method to align data timing between the segments. Through
the optimization of segment biasing and linear compensation,
we have achieved a bit error rate (BER) of 16QAM well below
the 20% forward error correction (FEC) threshold (2 × 10−2
).
Adding nonlinear pre-compensation allows for 32QAM with a
BER below the 24% FEC threshold (4.5 × 10−2
), enabling a
net rate of 483 Gbs per polarization. The modulator can also
be operated as an optical digital analogy converter for complex
optical signal generation, for which 100 Gbs is achieved for a
proof of concept
