Quantitative study of Silicon Waveguides for the Generation of Quantum Correlated Photon Pairs Bridging Mid-Infrared and Telecom Bands

TL;DR

This paper investigates silicon waveguides for generating quantum correlated photon pairs bridging mid-infrared and telecom bands using spontaneous four-wave mixing, providing designs with realistic operational parameters for quantum communication and sensing.

Contribution

It presents experimentally validated models and specific waveguide designs for efficient photon pair generation bridging mid-infrared and telecom bands in silicon photonics.

Findings

Achieved photon pair generation probability of 0.05 per pulse with realistic pump powers.

Designed waveguides with signal wavelengths up to 3.905μm in atmospheric transparency window.

Attained a signal/idler wavelength separation of 2364nm, surpassing previous records.

Abstract

Sources of quantum correlated photons pairs bridging the 3um-4um Mid-infrared (MIR) band and Telecom/Near-Infrared/Visible band are of high importance for quantum technologies. Spontaneous Parametric Down Conversion is generally used for realizing such sources, but requires costly implementation platforms with reduced versatility. Here, we explore the potentialities of Spontaneous Four-Wave Mixing (SFWM) in all-solid Silicon On Insulator (SOI) waveguides thanks to an experimentally validated model and propose designs ensuring the production of correlated photon pairs bridging the 3um-4um Mid-infrared band and Telecom C-band. Choosing a pump with a wavelength in the range 2100nm-2210nm and a pulse duration of 5ps, we quantitatively performed simulations targeting a probability of photon pair generation per pulse of 0.05, and we found realistic conditions of utilization (2cm-length straight waveguides, intra-modal Four Wave Mixing with the fundamental TE00 mode) with a pump peak power in between 9.2mW and 32mW. A first design (wCOM) reaches a signal wavelength as high as 3.905um, which is situated in an atmospheric transparency window, while maintaining an idler in the Telecom C-band, making it of high interest for atmospheric Quantum Key Distribution. Two other designs wCH4 and wNO2 aim precise CH4 and NO2 gas sensing with a signal wavelength of 3265nm and 3461nm respectively. In terms of signal/idler wavelength separation, wCOM attains the value of 2364nm which is well above the current record of ~1125nm obtained in quantum regime with SFWM in all-solid SOI waveguides.