Chirped Laser Dispersion Spectroscopy Sensitivity Booster

(Princeton Docket # 16-3267)

Inventors: Gerard Wysocki, Genevieve B. Plant, Yifeng Chen

Laser-based gas sensing has entered a new era of precision with this innovative technology designed to overcome traditional sensitivity limitations. By integrating a local oscillator channel and advanced signal processing, this solution delivers unparalleled accuracy in detecting trace gases across industrial, environmental, and safety applications.

This system splits a chirped laser beam into two arms:

• Sample Arm: Interacts with the target gas, generating multiple frequency components modulated by the gas’s dispersion profile.
• Local Oscillator (LO) Arm: Provides a frequency-shifted reference signal to amplify the heterodyne detection process.

After recombination, the mixed beam undergoes digital processing-notch filtering, frequency doubling, and demodulation-to extract dispersion spectra directly correlated with gas concentration. Compatible with free-space or fiber-coupled configurations, it supports single-sideband, dual-sideband, and frequency-comb setups

Key Innovations:

• Carrier-to-Noise Ratio (CNR) Boost: A strong LO signal amplifies the heterodyne gain, enhancing CNR by up to 100× compared to conventional methods.
• Noise Rejection: Harmonic fingerprint technology and multi-point verification minimize false alarms caused by interferent gases.
• Adaptable Configurations: Works with acousto-optic (AOM) or electro-optic modulators (EOM), enabling deployment in harsh or remote environments.

APPLICATIONS

ADVANTAGES

• Industrial Safety: Detect methane (CH₄), hydrogen sulfide (H₂S), and toxic gas leaks up to 200 meters6.
• Environmental Monitoring: Track greenhouse gases (CO₂, NH₃) with high precision over kilometer-scale paths7.
• Process Control: Optimize combustion efficiency in manufacturing using real-time gas concentration data4.
• Hazardous Environments: Monitor volatile compounds in chemical plants or confined spaces

• Enhanced sensitivity: Detects parts-per-billion (ppb) concentrations, critical for trace gas analysis.
• Robust Signal Integrity: Immune to amplitude fluctuations and phase noise from turbulence or vibrations.
• Low Maintenance: No consumable parts or frequent sensor replacements, reducing operational costs.
• Scalability: Integrates with frequency comb systems for multi-gas detection

Stage of Development

Prototype tested in a fiber-coupled system.

Contact
Renee Sanchez

New Ventures & Licensing Associate • (609) 258-6762 • renee.sanchez@Princeton.edu