Infrared Sensor Technology: Unlocking the Invisible Spectrum 2

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By David2m


From security systems to medical gadgets, infrared sensor technology has subtly transformed many industries. We’ll dive into the intriguing realm of infrared sensors in this in-depth blog post, looking at their workings, uses, and potential future developments.

How Do Infrared Sensors Work?

Beyond the visible spectrum, infrared light is detected using infrared sensors. These sensors translate an object’s thermal energy, or heat, into electrical impulses. They function in the near-infrared (NIR), mid-infrared (MIR), and far-infrared (FIR) wavelength ranges, among others.

How Do Thermal Sensors Operate?

Passive Infrared (PIR) Sensors: PIR sensors monitor variations in heat patterns and are utilised in motion detectors. A light or alert will go off when an object moves within the sensor’s range of view.

Active Infrared Sensors: These devices radiate infrared light on their own and track any energy that is reflected or absorbed. Gas sensing and distance measurement are two common uses.

Usages for Infrared Sensors

Protection and Monitoring

Systems for detecting intrusions.
Night vision cameras.
Detection of fire.

Automotive Sector

Customised Cruise Control.
Systems that prevent collisions.
Tyre pressure monitoring.

Medical Equipment and Healthcare

Thermometers without contact.
Monitoring of blood flow.
Measurement of oxygen saturation.

Environmental Observation

Detection of forest fires.
Evaluation of air quality.
Measurement of soil moisture.

Obstacles and Progress

Reduced Noise

Reducing the interference caused by outside sources sunlight, other electronics, etc.
Techniques for signal processing to improve accuracy.

Organic Photo diodes with Low Disorder

At wavelengths ranging from 800 to 1600, researchers have studied organic bulk hetero-junction photo diodes.
Significantly, when compared to devices that use Fuller derivatives, those that use non-Fuller accepts (NFAs) show reduced noise and increased detective.

Density-of-states data indicate that a dramatic drop-off in the distribution of band tail states is responsible for the low noise in NFA mixes.
The influence of thermal noise on effective band gap and band tail spread is explained by a broad physical model that takes disorder into account.

Light Field Imaging System for Fixed-Pattern Noise (FPN) Reduction

Non-uniform focal-plane-array microelectronic response is the cause of FPN, a problem in infrared and hyper spectral imaging.
A novel method digitises a scene’s light field and focuses it digitally on surrounding objects.

This method does not require in-depth knowledge of physical parameters or off-line black body sources, in contrast to standard techniques.

Reduction in size

Creating more compact, effective sensors for wearable and Internet of things devices.
Connectivity to smartwatches and smartphones.

Pixel Dimensions and Challenges

When it comes to imaging systems, pixel dimensions are essential in figuring out important parameters like weight, power consumption, and system size (SWaP). Better temperature and spatial resolution are attained with smaller pixels.
However, there are obstacles to pixel size reduction:

The aperture’s wavelength-dependent diffraction effects set a restriction on the maximum pixel size. Dim pixels may have a higher dark current, which degrades the clarity of the image. It is crucial to provide effective pixel hybridisation on the focal plane array (FPA). Performance depends on achieving exact pixel boundaries. As pixels get smaller, there is an increase in complexity in the efficient readout of unit cells.

Using Multi spectral Imaging

Using visible and infrared light together for improved imaging.
Finding concealed flaws in materials and artwork.

In summary

As infrared sensor technology advances, new developments in a variety of fields are made possible. In the upcoming years, anticipate even more fascinating uses as we uncover the unseen spectrum.


Can infrared sensors see past walls? No, solid objects like walls cannot be penetrated by infrared sensors. They pick up changes in surface temperature.

How safe are infrared sensors for people’s health? They do not cause harm to humans and are non-ionising.

What distinguishes infrared from ultrasonic sensors? Ultrasonic sensors employ sound waves to estimate distance, whereas infrared sensors rely on heat detection.

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