A Si ridge waveguide integrated with a lateral p-i-n diode forms a basic optical amplitude
and phase modulator. An efficient Si modulator is expected to establish a carrier concentration in
the waveguide with a minimum amount of electrical drive power.
We show that P<sup>+</sup> and N<sup>+</sup> doping sections that are recessed below the slab lead to lower power
consumption. This configuration is compared with alternative doping section arrangements. The
optimum arrangement results in less Si active area and reduced carrier recombination.
Effective carrier lifetimes of Si modulators based upon a lateral p-<i>i</i>-n structure were measured using
the reverse-recovery method. Modulators of two different waveguide dimensions were
characterized using this approach. Two additional lifetime measurement methods were used to
check against this method and showed consistent results. Finally the physical meaning of this
measured effective carrier lifetime was discussed in reference to its relationship with the diode
transit time, surface recombination velocity and the bulk carrier lifetime.
While investment in sub-wavelength silicon photonics research has gained popularity, Kotura has forged significant
customer traction with first generation silicon-photonics products by focusing on manufacturable designs and processes.
This paper reviews recent gains in engineering developments where mature monolithic and hybrid methods are
integrated to form high-performance manufacturable products with proven long-term reliability. Components and
methods are described that lead to photonic modules and subsystems suitable for automated manufacturing techniques.
This paper describes a silicon photonic circuit of eight fiber-optic input ports, each port leads through an electro-photonic modulator to a 0.95/0.05 coupler, where the 95% signal is guided to a fiber-optic output port and the 5% signal is terminated by a vertical coupler and a down-looking photodetector. Applications include telecommunication equipment requiring microsecond speed for rapid power balancing, transient suppression, and subcarrier modulation for channel tracking and system health monitoring. Circuit elements and initial measurements are described.
We report the design of a 10 GHz non-return-to-zero (NRZ) silicon modulator based upon 0.25-μm CMOS/BiCMOS processes. The basic optical component is a ridge waveguide slightly-doped with P and N impurities, which forms a reverse-biased P/N junction. The diode typically operates between reverse and zero biases, so as to change the number of free carriers overlapping with the optical mode and consequently modulate the phase of the light. This type of phase shifters form the arms of a push-pull Mach-Zehnder interferometer to realize amplitude modulation.