What Is an Infrared LED?
An infrared LED, or IR-LED or Ir-LED, is a light-emitting diode that produces infrared light. The term “IR” stands for “Infrared,” indicating light with a wavelength longer than visible red light. LEDs emit light when voltage is applied, making infrared LEDs capable of emitting near-infrared light within the 700 to 1,500 nm wavelength range.
Infrared light, characterized by its high transparency and minimal obstruction by obstacles, is invisible to the human eye. This makes it ideal for signal transmission/reception and as a light source for various sensors. Despite the availability of other infrared light sources, such as lasers, infrared LEDs are distinct for their mass production capability, longevity, resistance to shock, and cost-effectiveness.
Uses of Infrared LEDs
Infrared LEDs find applications across daily life and specialized fields, including:
- Remote controls for TVs and air conditioners
- Security camera lighting
- LiDAR and TOF camera light sources
- Moisture measurement in samples
- Night vision camera lighting
- Distance measurement devices for golf
- Smartphone and cellphone communication
Among the most common applications are remote controls for TVs and air conditioners, chosen for their ability to operate undetected by humans without adverse health effects. Additionally, “LiDAR” (Light Detection And Ranging) employs infrared LEDs for distance sensing, crucial for the development of autonomous driving technologies.
Principle of Infrared LEDs
The fundamental principle of LED light emission, applicable across all wavelengths, involves the p-n junction of semiconductors. Upon application of an electric field, holes migrate through the p-type semiconductor, while electrons move through the n-type semiconductor. The energy gap between the electrons and holes facilitates their collision upon perturbation, resulting in light and heat production. By varying the semiconductor composition, the emission wavelength can be tailored. Aluminum gallium arsenide (AlGaAs) is commonly used for near-infrared wavelengths, although infrared LEDs typically exhibit lower efficiency compared to their visible light counterparts.
Other Information on Infrared LEDs
1. Infrared LED Lights
Commercially available infrared LED lights cater to various applications, including night vision. Floodlights illuminate outdoor areas at night, employing multiple high-output infrared LEDs. Similarly, infrared LED flashlights, lightweight and sometimes featuring adjustable light quantities, support night activities. Compact night vision lights, designed for photography, ensure even lighting with a single high-output LED, boasting portability with lightweight designs and AA battery operation.
2. Infrared LED Tape
Infrared LED tape, designed for night vision camera auxiliary lighting, integrates infrared LEDs at regular intervals. Its adhesive backing facilitates easy application, with types available for confined spaces measuring 3 mm or thinner, offering versatility in use.