An ultralow power athermal silicon modulator

Abstract

Silicon photonics has emerged as the leading candidate for implementing ultralow power wavelength–division–multiplexed communication networks in high-performance computers, yet current components (lasers, modulators, filters and detectors) consume too much power for the high-speed femtojoule-class links that ultimately will be required. Here we demonstrate and characterize the first modulator to achieve simultaneous high-speed (25 Gb s−1), low-voltage (0.5 VPP) and efficient 0.9 fJ per bit error-free operation. This low-energy high-speed operation is enabled by a record electro-optic response, obtained in a vertical p–n junction device that at 250 pm V−1 (30 GHz V−1) is up to 10 times larger than prior demonstrations. In addition, this record electro-optic response is used to compensate for thermal drift over a 7.5 °C temperature range with little additional energy consumption (0.24 fJ per bit for a total energy consumption below 1.03 J per bit). The combined results of highly efficient modulation and electro-optic thermal compensation represent a new paradigm in modulator development and a major step towards single-digit femtojoule-class communications.

Exact solution to the steady-state dynamics of a periodically modulated resonator

“…The sideband components of the transmitted amplitude in this case are given by Eq. (18). With these new parameters, the best overlap with the target transmission is reached for ∆ω/Ω = 33.6, A 1 /Ω = 52.6, γ/Ω = 8.3, A 2 /Ω = 23.0, and φ m = 3.1.…”

“…2 The electro-optic modulator 3,4 is one of the most important components in silicon photonics, and CMOS-compatible, micrometer-scale devices based on a modulated cavity resonance have been a central focus of research. [5][6][7][8][9][10][11][12][13][14][15][16][17][18] Typically in these systems, a local refractive index change of the silicon results in a change of the transmission through the cavity. This is intuitively understood in the adiabatic limit, in which the modulation happens on a time scale that is much slower than the one given by the photon lifetime, but the phenomenology is in general much richer.…”

Broadband 10 Gb/s operation of graphene electro‐absorption modulator on silicon

“…Mach-Zehnder interferometer (MZI) and ring resonator based silicon modulators exploiting the plasma dispersion effect were extensively optimized over the past few years [3][4][5][6] and play a critical role in silicon transceiver prototypes emerging now [7][8][9]. However, MZI based modulators suffer from a large footprint, typically a few millimeters [6], and ring or disk modulators exhibit a narrow optical bandwidth, making them difficult to control and sensitive to temperature variations or fabrication errors [5]. Ge or SiGe electro-absorption modulators (EAM) are a promising alternative for these plasma dispersion based modulators.…”

Non-invasive monitoring and control in silicon photonics using CMOS integrated electronics

“…These considerations show that the integration of the CLIPP inside ultrasmall resonators with a radius of less than 5 μm [24] would require a higher readout frequency (several hundreds of megahertz). In this case, it could be more convenient to place the CLIPP outside the resonator.…”