Efficient wavelength conversion and net parametric gain via Four Wave Mixing in a high index doped silica waveguide

Abstract

We demonstrate sub-picosecond wavelength conversion in the C-band via four wave mixing in a 45cm long high index doped silica spiral waveguide. We achieve an on/off conversion efficiency (signal to idler) of + 16.5dB as well as a parametric gain of + 15dB for a peak pump power of 38W over a wavelength range of 100nm. Furthermore, we demonstrated a minimum gain of + 5dB over a wavelength range as large as 200nm.

New CMOS-compatible platforms based on silicon nitride and Hydex for nonlinear optics

“…Although self-phase modulation measurements are not overly dependent on dispersion (for waveguide lengths small compared with the dispersion length), for fourwave mixing, including parametric gain, dispersion is critical for efficient, wide bandwidth FWM including parametric gain [74,75]. Hydex waveguides have been engineered to yield anomalous dispersion over most of the C-band with the zero-GVD points being 1600 nm for a TE polarization and 1560 nm for TM [76].…”

“…Hydex waveguides have been engineered to yield anomalous dispersion over most of the C-band with the zero-GVD points being 1600 nm for a TE polarization and 1560 nm for TM [76]. This resulted in a large FWM wavelength tuning range with an efficient parametric gain of +15dB and a signal to idler conversion efficiency of +16.5dB [74].…”

Sub-picosecond phase-sensitive optical pulse characterization on a chip

“…The spiral waveguide was fabricated in the Hydex glass platform [27,28]. Films were deposited by plasma-enhanced chemical vapor deposition (PECVD) [25], and yielded low loss waveguides (at 1550nm) as deposited, without the requirement of high temperature annealing, thus making them ideal for a CMOS compatible fabrication process.…”

“…The resulting waveguide possesses a high effective nonlinearity (220W -1 km -1 ) due to a combination of tight mode confinement and high intrinsic n 2 , as well as a small and anomalous dispersion [26], and has very low linear (<6dB/m) and negligible nonlinear optical losses (up to 25GW/cm 2 ) [25,26]. This platform has shown excellent FWM performance -both in terms of conversion efficiency and bandwidth -with no appreciable gain saturation [28]. (b) X-SPIDER based on FWM: the PUT is split in two replicas and nonlinearly mixed with a highly chirped pump inside the chip (extracted from the same laser source in our set-up).…”

“…Our approach maintains the relative roles of the signal, the (external) pump and the idler that exist in the classical TWM implementation. The nonlinear optical component in our work is a 45-cm long spiral waveguide implemented in a high index, CMOS compatible, doped silica glass platform [25][26][27][28] (see Methods for details). The high nonlinear response exhibited by these waveguides [27,28] allows efficient wavelength conversion [25,26,28] throughout its anomalous dispersion regime, spanning from 1300nm to 1600nm [26].…”