Skip to main content
search

About the project

The Rationale

Human activities are driving climate change through greenhouse gas (GHG) emissions and worsening air quality, both of which pose serious threats to human health and ecosystems. To address these challenges, stricter environmental regulations are being introduced worldwide, but current air monitoring systems are not well-suited to meet these demands.

Commercially available sensors are costly, large, and often rely on mains power and protective shelters. Additionally, their field performance is often inadequate due to issues like high signal noise and drift. As a result, there is a growing need for new air pollution and GHG monitoring technologies that provide better sensitivity, precision, and accuracy, while being affordable, compact, and energy-efficient to meet the new, more stringent, environmental standards.

 

The Objective

The primary goal of the RAVEN project is to design and develop two innovative, complementary, compact, and cost-effective sensors based on photonic integrated circuits (PICs). These sensors will work together to provide continuous gas analysis over a wide wavelength range (600-3000 nm), enabling the detection and measurement of numerous analytes with high sensitivity, accuracy, and precision.

The sensors will undergo evaluation with end users in laboratory settings that simulate real-world conditions across various applications. These include monitoring greenhouse gases and air pollutants in terrestrial environments, quantifying dissolved methane in seawater for climate change impact studies and offshore pipeline leak detection, and measuring concentrations of methane, methanol, and ammonia above surface waters to monitor and research episodic pollution events.

The Technology

The two sensors will incorporate a total of four integrated photonic circuits (PICs). The VIS-SWIR gas sensor system will consist of three PICs:

  • PIC 1 will be a powerful, affordable, and compact supercontinuum light source designed for gas sensing. This chip aims to have minimal coupling loss and an overall power output of about 100 mW. It will include a high-peak microchip laser and a LiNbO3 waveguide operating in the 400-1700 nm range with a waveguiding loss of no more than 1 dB/cm.
  • PIC 2 will consist of gas-sensing components designed to function in harsh environments. It will feature a double spiral waveguide for evanescent sensing, combined with a Bloch Surface Wave platform to detect gases within the 600-1700 nm spectral range.
  • PIC3 will be a data processing chip that employs both standard and heterodyne interferometry on a SiO2 chip. This chip will utilise a hybrid polymer/TiO2 waveguide to enable on-chip data analysis using a quantum-inspired approach, improving the limit of detection and selectivity for various gases.

The MIR sensor will revolve around PIC 4 and feature a compact photoacoustic cell (PAC) integrated with a tunable MIR laser. This system will be capable of detecting gases such as CO₂, CO, CH₄, NH₃, and N₂O, with detection limits varying between 1 and 10 parts per billion (ppb), depending on the specific gas.

The table on the right lists absorption bands and expected LOD for the gases targeted by RAVEN sensors. LOD market with * assume 5mV optical power.

Project structure

RAVEN project is divided into seven work packages (WP):

  • WP1: Supercontinuum source development (PIC 1)
  • WP2: Sensing chip development (PIC 2)
  • WP3: Data processing chip development (PIC 3)
  • WP4: MIR sensor development and packaging (PIC 4)
  • WP5: Integration, valorisation, validation and exploitation
  • WP6: Measures to maximise impact
  • WP7: Project management and coordination