Low-voltage high-performance silicon photonic devices and photonic integrated circuits operating up to 30 Gb/s

Abstract

We present high performance silicon photonic circuits (PICs) defined for off-chip or on-chip photonic interconnects, where PN depletion Mach-Zehnder modulators and evanescent-coupled waveguide Ge-on-Si photodetectors were monolithically integrated on an SOI wafer with CMOS-compatible process. The fabricated silicon PIC(off-chip) for off-chip optical interconnects showed operation up to 30 Gb/s. Under differential drive of low-voltage 1.2 V(pp), the integrated 1 mm-phase-shifter modulator in the PIC(off-chip) demonstrated an extinction ratio (ER) of 10.5dB for 12.5 Gb/s, an ER of 9.1dB for 20 Gb/s, and an ER of 7.2 dB for 30 Gb/s operation, without adoption of travelling-wave electrodes. The device showed the modulation efficiency of V(π)L(π) ~1.59 Vcm, and the phase-shifter loss of 3.2 dB/mm for maximum optical transmission. The Ge photodetector, which allows simpler integration process based on reduced pressure chemical vapor deposition exhibited operation over 30 Gb/s with a low dark current of 700 nA at -1V. The fabricated silicon PIC(intra-chip) for on-chip (intra-chip) photonic interconnects, where the monolithically integrated modulator and Ge photodetector were connected by a silicon waveguide on the same chip, showed on-chip data transmissions up to 20 Gb/s, indicating potential application in future silicon on-chip optical network. We also report the performance of the hybrid silicon electronic-photonic IC (EPIC), where a PIC(intra-chip) chip and 0.13μm CMOS interface IC chips were hybrid-integrated.

Recent breakthroughs in carrier depletion based silicon optical modulators

“…The first designs of this type were demonstrated in 2008 [21][22][23], and since then there have been numerous versions published with different variants in the design [24][25][26][27][28][29][30][31][33][34][35][36][37]. The most straightforward form of the device has the pn junction positioned in the waveguide equidistant from the rib edges [25][26][27][28][29][30][31][32].…”

A CMOS-compatible silicon photonic platform for high-speed integrated opto-electronics

“…1 Kim et al have demonstrated both modulators and detectors working at speeds of 30 Gb/s. 2 Just recently, IMEC announced the upcoming launch of a fully integrated 25 Gb/s platform via the ePIXfab MPW.…”

Vertical grating coupler-based silicon photonic devices and photonic integrated circuits on CMOS-compatible SOI platform

“…Numerous and impressive works have been reported in the field of silicon photonics in recent years [1][2][3][4][5]. The advantage of silicon photonics is its compatibility with silicon microelectronic process.…”

“…Ring-resonator enhanced silicon modulators and germanium photodetectors was monolithically integrated and 3Gb/s optical link was demonstrated [1]. Higher speed off-chip/on-chip photonic interconnects was also illustrated by monolithically integrating PN depletion Mach-Zehnder modulators and Ge-on-Si photodetectors [2]. Ring modulator with improved electro-optic efficiency and Ge waveguide detector were hybrid integrated with driver circuit and receiver circuit respectively [3].Monolithic integration of the silicon photonic components and electronic circuits was performed by Luxtera [4] and IBM [5].…”