Our recent theoretical and experimental investigation of the photothermal effect in a planar metamaterial absorber is
reviewed in the present paper. The observed ultrasensitive photothermal heating in such an absorber nanostructure
irradiated by a pulsed white-light source is elaborated with a simple yet compelling heat transfer model, which is
subsequently solved with a finite-element method. The simulation results not only agree with the experimental finding,
but also provide more detailed understanding of the temperature transition in the complex system.
We experimentally demonstrate an efficient coupler between a silicon waveguide and a hybrid
plasmonic waveguide for the wavelength range 1460-1540 nm. The coupling efficiency for a single
coupler is ~70% in the whole spectrum range which is consisted with the theoretical prediction. Such
compact, efficient plasmonic couplers provide a promising platform for integrated photonic circuits.
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 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.