Working principle of infrared emission tube

Infrared emission tube is also called infrared emission diode, which belongs to light-emitting diode. It is a kind of light-emitting device that can directly convert electric energy into near-infrared light (invisible light) and radiate it. It is mainly used in various photoelectric switches and remote control transmitting circuits. The structure and principle of the infrared emission tube are similar to that of the ordinary led, but the semiconductor materials used are different. Infrared light-emitting diodes are usually made of gallium arsenide (GaAs), gallium arsenide (GaAlAs) and other materials, which are all transparent or light blue and black resin package.
Infrared emission tube, also known as infrared emission diode, is composed of infrared light-emitting diode. The infrared emitting diode is made of materials with high infrared radiation efficiency, such as gallium arsenide (GaAs), gallium arsenide (GaAlAs) and so on. The spectral power distribution is from 830 nm to 950 nm, and the half peak bandwidth is about 40 nm. It is a narrow band distribution, which can be felt by ordinary CCD black-and-white camera. Its biggest advantage is that there is no red burst completely (using 940-950nm wavelength infrared tube) or only weak red burst (red burst has visible red light) and long service life.
The emission power of the infrared light-emitting diode is expressed by irradiance μ w / cm2 or MW / m2. Generally speaking, the infrared radiation power is directly proportional to the forward working current, but when it is close to the maximum rated value of the forward current, the temperature of the device rises due to the heat consumption of the current, so that the optical emission power decreases. If the current of the infrared diode is too small, it will affect its radiation power, but if the working current is too large, it will affect its life and even burn down the infrared diode.
When the voltage crosses the forward threshold voltage (about 1.0V), the current begins to flow, which is a very steep curve, indicating that the working current is very sensitive to the working voltage. Therefore, the working voltage is required to be accurate and stable, otherwise the radiation power and its reliability will be affected. The radiation power will decrease with the increase of ambient temperature (including the rise of ambient temperature generated by its own heating). In the design and selection of infrared lamps, especially for long-distance infrared lamps, the heat consumption should be paid attention to.
The maximum radiation intensity of the infrared diode is generally in the front of the optical axis, and decreases with the increase of the angle between the radiation direction and the optical axis. The angle of 50 [%] of the maximum radiation intensity is called the half intensity radiation angle. The radiation angle of different packaging process models is different.