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

Abhishek Pandey, Deepak Jain+1 more|arXiv (Cornell University)|Feb 18, 2026

Spectroscopy and Laser Applications0 citations

TL;DR

The paper analyzes spontaneous four-wave mixing in all-solid SOI waveguides to generate quantum-correlated photon pairs bridging 3–4 μm MIR and telecom bands, presenting designs and quantitative conditions for high-wavelength separation and practical pump powers.

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.

Motivation & Objective

• Motivate quantum technologies by bridging MIR (3–4 μm) and telecom bands with correlated photon pairs.
• Assess feasibility of SFWM in all-solid SOI waveguides using experimentally validated models.
• Propose waveguide designs and pump conditions to maximize pair-generation probability per pulse under practical constraints.
• Identify designs enabling specific MIR signal wavelengths for atmospheric sensing or gas detection.

Proposed method

• Use an experimentally validated SFWM model in silicon-on-insulator waveguides.
• Simulate 2 cm straight waveguides supporting intra-modal SFWM with fundamental TE00 mode.
• Choose pump in 2100–2210 nm with 5 ps pulse duration to target a pair-generation probability per pulse of 0.05.
• Analyze designs to achieve large signal-idler separation and MIR telecom bridging.
• Evaluate signal wavelengths for designated applications (MIR atmospheric window, CH4/NO2 sensing).
• Report practical pump peak powers (9.2–32 mW) to reach the target generation probability.

Experimental results

Research questions

• RQ1 Can SFWM in all-solid SOI waveguides produce correlated photon pairs bridging 3–4 μm MIR and telecom bands under realistic pump conditions?
• RQ2 What pump wavelengths, pulse duration, and waveguide lengths enable a pair-generation probability per pulse of 0.05 in 2 cm straight TE00 waveguides?
• RQ3 What are the achievable signal and idler wavelength pairs for designs optimizing MIR-telecom separation and application-specific requirements (atmospheric window, CH4/NO2 sensing)?

Key findings

• A 2 cm straight waveguide with intra-modal SFWM in TE00 mode can achieve 0.05 pair-generation probability per pulse with pump peak powers of 9.2–32 mW.
• The wCOM design yields a signal up to 3.905 μm and an idler in the Telecom C-band, with a signal–idler separation of 2364 nm.
• The wCOM separation (2364 nm) surpasses the current record of ~1125 nm for SFWM in all-solid SOI waveguides.
• The wCH4 and wNO2 designs target MIR signals at 3265 nm and 3461 nm, respectively, for CH4 and NO2 gas sensing.
• The MIR–telecom bridge design demonstrates atmospheric QKD suitability due to the MIR signal within an atmospheric window.