Adiabatic microring modulators.

In this work, we demonstrate and experimentally characterize a new class of high-performance silicon photonic modulators-the adiabatic microring modulator. The adiabatic microring modulator utilizes a vertical PN junction and interior electrical contacts, leveraging all the advantages of previously-demonstrated microdisk modulators. However, this device also incorporates an adiabatic transition from the wide, multimode contact region, to a narrow, single-mode coupling region, eliminating unwanted spatial modes common to microdisks.

Low-voltage differentially-signaled modulators.

For exascale computing applications, viable optical solutions will need to operate using low voltage signaling and with low power consumption. In this work, the first differentially signaled silicon resonator is demonstrated which can provide a 5dB extinction ratio using 3fJ/bit and 500mV signal amplitude at 10Gbps. Modulation with asymmetric voltage amplitudes as low as 150mV with 3dB extinction are demonstrated at 10Gbps as well.

Ultra compact 45 GHz CMOS compatible Germanium waveguide photodiode with low dark current.

We present a compact 1.3 × 4 μm2 Germanium waveguide photodiode, integrated in a CMOS compatible silicon photonics process flow. This photodiode has a best-in-class 3 dB cutoff frequency of 45 GHz, responsivity of 0.

Vertical junction silicon microdisk modulators and switches.

Vertical junction resonant microdisk modulators and switches have been demonstrated with exceptionally low power consumption, low-voltage operation, high-speed, and compact size. This paper reviews the progress of vertical junction microdisk modulators, provides detailed design data, and compares vertical junction performance to lateral junction performance. The use of a vertical junction maximizes the overlap of the depletion region with the optical mode thereby minimizing both the drive voltage and power consumption of a depletion-mode modulator.

Silicon photonics manufacturing.

Most demonstrations in silicon photonics are done with single devices that are targeted for use in future systems. One of the costs of operating multiple devices concurrently on a chip in a system application is the power needed to properly space resonant device frequencies on a system's frequency grid. We asses this power requirement by quantifying the source and impact of process induced resonant frequency variation for microdisk resonators across individual die, entire wafers and wafer lots for separate process runs.