Ultralow drive voltage silicon traveling-wave modulator

Abstract

There has been great interest in the silicon platform as a material system for integrated photonics. A key challenge is the development of a low-power, low drive voltage, broadband modulator. Drive voltages at or below 1 Vpp are desirable for compatibility with CMOS processes. Here we demonstrate a CMOS-compatible broadband traveling-wave modulator based on a reverse-biased pn junction. We demonstrate operation with a drive voltage of 0.63 Vpp at 20 Gb/s, a significant improvement in the state of the art, with an RF energy consumption of only 200 fJ/bit.

High-Speed, Low Drive-Voltage Silicon-Organic Hybrid Modulator Based on a Binary-Chromophore Electro-Optic Material

“…In particular, carrier-injection devices feature voltage-length products as small as U π L = 0.36 Vmm, but free-carrier lifetime limits modulation speed to few Gbit/s if no pre-emphasis of the drive signal is used [2]. In contrast, carrier-depletion modulators support symbol rates of up to 50 GBd [4], but typical voltage-length products are beyond 10 Vmm [5], [6] and thus much larger than those of injection-type devices. Drive voltage and device footprint can be strongly reduced by using resonant structures [5], [7].…”

Compact Verilog-A modeling of silicon traveling-wave modulator for hybrid CMOS photonic circuit design

“…A top view illustration of the MZM fabricated by Op-SIS/IME with a cross-section view of the lateral pn junction arm is shown in Fig.1 [4]. The waveguide core consists of lightly doped pn junction, intermediate density p + and n + regions for reducing series resistance without inducing excessive optical loss, and heavily doped p ++ and n ++ implant for contact [4], [5].…”

“…The waveguide core consists of lightly doped pn junction, intermediate density p + and n + regions for reducing series resistance without inducing excessive optical loss, and heavily doped p ++ and n ++ implant for contact [4], [5]. The working mechanism of the MZM is described next.…”

“…When combining the two paths of light together, they interfere either constructively or destructively as seen at the output depending on the E-field selectively applied across their arms. The electro-optic effect used to modulate optical phase in such a device is based on free carrier dispersion mechanism, which can achieve higher modulation speed than the forwardbias carrier injection mechanism [4].…”

High-Speed Silicon-Organic Hybrid (SOH) Modulator with 1.6 fJ/bit and 180 pm/V In-Device Nonlinearity

“…Carrier depletion modulators, in contrast, have been demonstrated to operate at data rates of up to 50 Gbit/s [5], but typically with π V L > 10 Vmm for non-resonant devices. Extinction ratios (ER) range from 3 dB to 8 dB at high data rates, and the lowest reported energy consumption is 200 fJ/bit [6]. Modulation energies can be significantly reduced by using resonant structures, such as ring resonators, microdisks or photonic crystal waveguides.…”