Accurate photonic analog-to-digital conversion

Photonic analog-to-digital converters (ADCs) are attracting significant interest due to promise of overcoming the problem of aperture jitter and improving ADC performance level by orders of magnitude. This work examines several critical factors which define the accuracy of an optically-sampled wavelength-demultiplexed ADC built on a silicon chip using silicon photonic technology. These factors are the optical power-dependent shot noise, optical power-dependent nonlinearities due to two-photon and free-carrier absorption in silicon, and nonlinear transfer function of a silicon modulator. Ways to reduce the impact of these factors on ADC accuracy are considered.