Phase-sensitive optical pulse characterization on a chip via Spectral Phase Interferometry for Direct Electric-Field Reconstruction (SPIDER)

TL;DR

This paper presents a chip-based, phase-sensitive optical pulse measurement technique using a novel SPIDER variation that enables ultrafast pulse characterization with low power and broad bandwidth.

Contribution

A new integrated device utilizing degenerate FWM in CMOS technology for simultaneous amplitude and phase measurement of ultrafast pulses.

Findings

Measures pulses with <100mW peak power

Achieves >1THz bandwidth

Handles up to 100ps pulsewidths

Abstract

The recent introduction of coherent optical communications has created a compelling need for ultra-fast phase-sensitive measurement techniques operating at milliwatt peak power levels and in time scales ranging from sub-picoseconds to nanoseconds. Previous reports of ultrafast optical signal measurements in integrated platforms[8-10] include time-lens temporal imaging on a silicon chip[8,9] and waveguide-based Frequency-Resolved Optical Gating (FROG). Time-lens imaging is phase insensitive while waveguide-based FROG methods require the integration of long tuneable delay lines - still an unsolved challenge. Here, we report a device capable of characterizing both the amplitude and phase of ultrafast optical pulses with the aid of a synchronized incoherently-related clock pulse. It is based on a novel variation of Spectral Phase Interferometry for Direct Electric-Field Reconstruction (SPIDER)that exploits degenerate four-wave-mixing (FWM) in a CMOS compatible chip. We measure pulses with <100mW peak power, a frequency bandwidth >1THz, and up to 100ps pulsewidths, yielding a time-bandwidth product (TBP)>100.