Matching p-i-n-junctions and optical modes enables fast and ultra-small silicon modulators

Abstract

In this article a new method is presented that allows for low loss implementation of fast carrier transport structures in diffraction limited photonic crystal resonators. We utilize a 'node-matched doping' process in which precise silicon doping results in comb-like shaped, highly-doped diode areas that are matched to the spatial field distribution of the optical modes of a Fabry-Pérot resonator. While the doping is only applied to areas with low optical field strength, the intrinsic diode region overlaps with an optical field maximum. The presented node-matched diode-modulators, combining small size, high-speed, thermal stability and energy-efficient switching could become the centerpiece for monolithically integrated transceivers.

Silicon photonics interconnect based on ultra-small scalable components for multi-channel optical transceivers

“…The presented work was using a node-matched diode (NMD) modulator device which was first presented in [4], with overall modulator footprint below 100 µm 2 , including contacts of the diode. The modulator structure consists of a silicon nanowire rib waveguide with lateral dimensions of 220×450 nm 2 .…”

Compact 1D-silicon photonic crystal electro-optic modulator operating with ultra-low switching voltage and energy

“…Both effects contribute to making the carrier injection process faster. An improvement in modulation speed by reducing the intrinsic region width through the use of a comb-shaped doping profile is reported in [27]. Furthermore, reducing the gap between p and n regions will further improve the performance of the device by reducing the resistance.…”

Slow light with interleaved p-n junction to enhance performance of integrated Mach-Zehnder silicon modulators

“…The grating waveguides considered here have the advantage of being more compatible with standard silicon photonic circuits on widespread industrial platforms, especially because the structure is simpler and less demanding in terms of optical design and fabrication, and low-loss tapers with standard rib waveguides are easily available. Resonator-based modulators with interleaved p-i-n junctions leading to matching with optical mode have also been developed [38][39][40]. Such resonators have typically a small bandwidth, unlike the MZ modulators proposed in this work.…”