Infrared detectors are optoelectronic devices that detect infrared radiation emitted by objects. The radiation is invisible to the human eye, but its detection makes it possible to accurately analyse temperature, identify materials, and track objects in conditions of limited visibility. Infrared detectors are used in many fields, including thermal imaging, industry, medicine, defence, and monitoring and security systems. Depending on the application, these detectors can operate in different infrared ranges (near, mid, and far), which determines their design and operation.
Infrared Detectors
Type of technology
Description of the technology
Basic elements
- Active material: A semiconductor material, such as HgCdTe (mercury cadmium telluride), InSb (indium antimony), or InGaAs (gallium indium arsenide), that absorbs infrared radiation and generates an electrical signal.
- Detection system: Photodiodes, bolometers, thermopiles, or other structures that detect radiation and convert it into a measurable signal.
- Cooling system: Cryogenic cooling systems (e.g. Stirling) used in far-infrared detectors to reduce thermal noise.
- Signal processing electronics: Signal amplification and analysis modules for clear measurement results.
- Input optics: Lenses and optical filters that concentrate infrared radiation on the detector surface and eliminate unwanted wavelength ranges.
Industry usage
- Medicine: Thermal imaging for inflammation detection and cancer diagnosis.
- Energy: Monitoring temperature distribution in power grids.
- Industry: Quality control of welding processes and detection of gas leaks.
- Cybersecurity: Perimeter surveillance and perimeter protection systems.
- Automotive industry: Advanced driver assistance systems (ADAS) based on infrared object detection.
Importance for the economy
Infrared detectors are widely used in various economic sectors, such as industry, energy, public safety, and health care. In industry, they enable monitoring of the condition of machinery and equipment, which contributes to increased safety and reduced operating costs. In medicine, thermal imaging techniques enable non-contact diagnosis of inflammatory conditions and monitoring of patients’ vital signs. In the security sector, infrared detectors are a key component of surveillance systems and perimeter protection, helping to increase the security of critical infrastructure.
Related technologies
Cybersecurity
Securing data from thermal imaging systems against unauthorised access and manipulation.
Big Data
Processing and analysing large data sets from thermal monitoring systems to identify anomalies.
Internet of Things
Integration with IoT sensor networks for remote monitoring and real-time data transmission.
Mechanism of action
- Infrared detectors use the absorption of infrared radiation by a semiconductor material, which results in the generation of an electrical signal proportional to the intensity of the radiation. In the case of photon detectors, such as HgCdTe, infrared radiation is absorbed by electrons, which move to a higher energy level, generating an electric current flow. Thermal detectors, such as bolometers, measure temperature changes caused by the absorption of infrared radiation, which leads to a change in the material’s resistance. Depending on the type of detector, the signal is amplified, filtered, and processed by electronic circuits to obtain precise information on temperature distribution or the presence of specific substances.
Advantages
- High sensitivity: Ability to detect small changes in temperature and infrared radiation.
- Working in the dark: Object detection even in the absence of visible lighting.
- Remote monitoring: Ability to monitor objects from a distance.
- Non-contact detection: Operational safety when measuring under hazardous conditions.
- Multifunctionality: They can be used in a wide range of applications, from medicine to defence.
Disadvantages
- High production costs: Infrared detectors, especially those based on advanced materials, are expensive to manufacture.
- Complexity of cooling systems: They require advanced cooling systems, which increases operating costs.
- Sensitivity to interference: Thermal interference can affect the accuracy of measurements.
- Limited lifetime: Cooling components and detectors based on semiconductor materials can wear out quickly.
- Regulatory problems: Export regulations may restrict the use of advanced detectors in some countries.
Implementation of the technology
Required resources
- Advanced semiconductor materials: Materials, such as HgCdTe, InSb, InGaAs, and other semiconductors, used to manufacture infrared detectors.
- Cooling systems: Cryogenic cooling systems to reduce thermal noise.
- Precision optical systems: Lenses and filters for infrared radiation analysis.
- Processing software: Signal analysis and data visualisation tools.
- Specialists in photonics and metrology: Experts to design, install, and test infrared detection systems.
Required competences
- Infrared technology: Knowledge of the principles of operation and application of IR detectors.
- Design of detection systems: Creating systems to detect signals in the infrared band.
- Analogue electronics: Design and construction of amplifiers for IR signals.
- Physics of materials: Knowledge of the properties of semiconductor materials used in IR detectors.
- Security of IR systems: Implementation of methods to protect against interference and unwanted IR emissions.
Environmental aspects
- Energy consumption: High energy demand in systems with advanced cooling.
- Emissions of pollutants: Emissions from the production of advanced semiconductor materials.
- Waste generated: Difficulties in disposing of semiconductor materials and optical components.
- Recycling: Problems with recycling detectors containing heavy metals and toxic compounds.
- Raw material consumption: High demand for rare metals and specialised materials.
Legal conditions
- Protection of intellectual property: Regulations for patent protection of infrared detection technological solutions, including specialised semiconductor materials, detection methods, and signal processing methods.
- Safety of use: Standards for working with infrared detectors, especially those that operate in the high energy range or require advanced cooling (e.g. cryotechnology regulations).
- Environmental regulations: Standards for waste management and recycling of semiconductor materials and for minimising emissions during detector production.
- Product certification: Requirements for certification of detectors and equipment in the context of their safety, reliability, and compliance with electromagnetic standards (e.g. CE and IEC).
- Export regulations: Export regulations for advanced infrared detection technologies that can be considered dual-use technologies (e.g. ITAR and EAR).