We experimentally demonstrate all-optical signal processing functions using silicon microring resonators with a
450×250-nm cross section. These results include slow-light delay of phase-modulated data and microwave
photonic signal, wavelength conversion/multicasting, format conversions, optical differentiation, and concentric
micro-ring resonators with deeper notches for label-free bio-sensing applications.
We propose a prototype of a silicon-chip-based frequency quadrupling system integrating a single-drive silicon Mach-
Zehnder modulator and a race-track resonator as an optical differentiator. A proof-of-concept demonstration of 40-GHz
millimeter-wave signal generation using 10-GHz driving signal is experimentally provided. The factors that impacting
the purity of the RF spectrum are discussed through simulation.
We propose and experimentally demonstrate all optical format conversion from non-return-to-zero (NRZ) format to
frequency-shift-keying (FSK) format based on free carrier dispersion effect in a silicon mode-split microring resonator.
The injection of the high-power NRZ signal generates free carriers leading to the blue shift of the spectrum when a '1'
comes. Therefore, there is a selective filtering for the two probes with certain separation located at different position of
the split mode according to the information carried by the NRZ signal. Then the NRZ signal is converted to the FSK
format. The microring resonator features ultra-compact size with a radius of 10 μm thus is suitable for integration with
silicon-on-insulator (SOI) based optical and electronic devices. The split mode can provide large and variable frequency
deviation for the FSK signal. 1 Gb/s NRZ signal is successfully converted to FSK format with a frequency deviation of
40 GHz, which can find application for interconnection between a metropolitan area networks (MAN) and a passive
optical network (PON) system.
We show that a ring resonator with mutual modes coupling can achieve pulse delay or advancement of tens nanoseconds,
which is similar as a ring resonator with single mode. Nevertheless, the pulse response can be sensitively
tunable either through mutual mode coupling or through waveguide-ring coupling in the vicinity of resonant frequency.
We experimentally demonstrate optically tunable buffer in a
nano-scale silicon microring resonator with a 20-μm
radius. The delay-tuning mechanism is based on the red shift of the resonance induced by the thermal nonlinear
effect. We use a non-return-to-zero (NRZ) pseudo random bit sequence (PRBS) signal with different data rates as
the probe signal, and investigate its delay performance under different pump powers.