What Is The Wavelength Of Light Emitted By LED?


Typically, LEDs (light-emitting diodes) are semiconductors that usually convert electrical energy to light energy. The emitted light color depends on the materials of a semiconductor and its composition. LEDs are categorized into three wavelengths, i.e., ultraviolet, visible, and infrared. The commercial LEDs wavelength with a single-element output of 5Mw is between 275 to 950 nm. 

Each wavelength range comes from a particular semiconductor material family, and it doesn’t matter the manufacturer. Meaning, the actual color of LED is achieved by the wavelength of the light emitted, which is decided via the actual semiconductor material used in establishing the PN function. 

So, LED is not determined by the coloring of its plastic body. However, companies use it to enhance light output and indicate its color when not in use. When you have the light of a specific wavelength, you will only see that color. Each object has color since they reflect a particular wavelength of light more than others. But unlike its counterparts such as incandescent or stars, LED can only emit a specific few wavelengths if electrically excited. 

Wavelength Of Light Emitted By LED

What Type Of Light Is Emitted From A LED?

LEDs emit numerous wavelength lengths in different categories, i.e., ultraviolet, visible, and infrared regions, in agreement with their bandgap energy. Notably, white LEDs offer low power consumption and long life than traditional light bulbs, which is why it increasingly dominates the lighting. These white LEDs are used for many applications for display and lighting, such as LCD backlight customarily used for traffic lights, cellphones, flashlights, road signs, and out displays, etc.

Ultraviolet LEDs (UV LEDs): 240- 360 nm

It is specifically made for industrial applications, medical/biomedical, and water disinfection. Energy output extent is more than 100 Mw for a wavelength as short as 280 nm. The materials solely used for UV LEDs are aluminum gallium nitride/gallium nitride (InGaN/GaN) at 360nm wavelengths or longer. Shorter wavelengths utilize proprietary materials. Simultaneously, the market of 360nm wavelength or longer is stabilizing due to plentiful supplies and lower prices.  On the other hand, few suppliers manufacture shorter wavelengths, and that’s why its price remains high than the rest of the LED product offerings.

Near-UV To Green LEDs: 395-530 nm

The material product used for this wavelength range is indium gallium nitride (InGaN). And as much as it’s possible to make some wavelengths, technically around 395 to 530 nm, large suppliers concentrate mainly on generating blue LEDs that are between 450 to 475 nm. This is generally for creating white light phosphors, plus green LEDs with 520 to 530 nm for traffic light green signal lighting. People view LED technology as mature. Its improvements in optical efficiency have stopped or slowed down in the last few years.

Yellow-Green To Red LEDs: 565-645nm

The semiconductor used for this wavelength range is Aluminum indium gallium (AllnGaP). Its specifically used to make the yellow traffic signal (590nm) and the red traffic signal (625nm).  Other lights available in this technology are lime-green or yellowish-green (565 nm) plus orange (625). However, their availability is limited.

Interestingly, neither the AllnGaP nor InGaN technologies are accessible as pure green (555nm) emitters. The pure green region exists in less efficient and older technologies. However, they are not as bright or efficient, mainly due to low demand/ lack of interest from the marketplace and lack of finances to design alternative material technology for the wavelength.

Deep Red To Near-Infrared (IRLEDs): 660-900 nm

Various variations on the device structure in these ranges are there. However, all use gallium arsenide (GaAs) or aluminum gallium arsenide (GaAs) materials. Such applications include; night vision illumination, industrial photo controls, remote control, and many medical applications9 at 660 to 680 nm).

What Is The Wavelength Of A Red LED?

Incompatible LED compound emits lights in some evident light spectrum, thus generating dissimilar intensity levels. The choice required for the semiconductor material used brings the overall wavelengths of lights emission. The results being the color of the light emitted. The wavelength of the red LED lies between 630-660 nm.

The table below helps you to understand different color wavelengths: 

Typical LED Characteristics



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Semiconductor Materials

850-940 nm




630-660 nm




605-620 nm




585-595 nm



GaAsP: N









450 nm




Which Color Has The Highest Wavelength?

The color with the highest wavelength for LEDs is Red, while violet has the shortest wavelength. But, when all lights are sighted together, they form white light. Its wavelength is between 630-660 nm, and the semiconductor’s material is GaAsP. 

What Is The Best Wavelength For Red Light Therapy?

Red light therapy is one top-rated healing tools reviewed as painless, safe, drug-free, and non-invasive. It is a form of treatment for healing skin and the body. Its best wavelengths are between 625 to 900 nm range and are considered the most efficient.

How Does Red Light Therapy Work?

Generally, the red light wavelength influences bodily cells on a biochemical measure by increasing mitochondrial function to generate cellular energy.  When the cellular energy generations are more, the body functions better as a whole. If you use red light therapy on your skin surface, it can penetrate up to 8-10 millimeters into the skin.

This type of therapy started more than 40 years ago. The wavelength of light can repair, restore and offer protection to body tissue that might be degenerating, injured, or at risk of dying. However, wavelengths impact our bodies differently. The highly effective level is between 625 to 900nm wavelength range for red light healing therapy. 

The Benefits Of Red-Light Therapy

Red light therapy works starting inside out to improve mitochondrial functioning in the cells. Which in turn forms many skin benefits. It can help the body repair sun damage, decrease skin inflammations, and fade scars, stretch marks, or smooth skin tone. It can even build up collagen in your skin which minimizes wrinkles while helping heal the wound. This kind of therapy also positively affects the lymphatic system by improving the blood flow and your body’s ability to detoxify. Other key benefits include;

1. Enhanced fertility

2. Minimize pain


3. Increased muscle recovery

4. Anti-inflammatory impact

5. Radiant skin

6. Increased testosterone

7. Minimizes fine lines, scars, and wrinkles

8. Speed up wound healing

9. Improve collagen generations and many more. 

What Is Wavelength?

You can define wavelength as the distance between 2 successive troughs or crests of a wave. Typically measured in the direction of the wave.

So, it is the distance from one crest to the other or from one trough to another wave which might be a sound wave, electromagnetic wave, or any other type of wave. Whereas the crest is the highest point of the wave, the trough remains the lowest.

How Can You Calculate The Wavelength Of An LED?

Because the wavelength is distance/length, their measurement is in units like millimeters, nanometers, meters, centimeters, etc. You can easily calculate the wavelength of a LED using wavelength equation or wavelength formula, which is as follows;

Wavelength = v/f where ‘V stands for the speed of the wave, whereas ‘f” stands for the frequency.

So basically, the wavelength of the wave equals the speed of the wave over its frequency. For example, when the speed wave is 650m per second while the frequency is thirty waves per second, the wavelength calculations is

Wavelength = 650/30

                    = 21.6 m

Note that the wavelength of light differs with colors. Whereas red color has the longest wavelength, violet has the least. The UV radiation wavelength is usually shorter than violet light. In contrast, the infra-red radiation wavelength is longer than the red light wavelength. Usually, the wavelength is likewise proportional to frequency. Meaning the longer the wavelength have lower frequencies and vice versa.

Is It Easy To Determine The Exact Wavelength Of A Color Change?

The color is decided first by frequencies that mix when they reach our eyes. Let’s start by relating to what a typical person would see if looking at electromagnetic radiation of a single frequency commonly known as monochromatic light by physicists. It means single color in layman’s language but meaning “single frequency.” 

The radiation of low frequency is invisible. Many humans begin to perceive dull red color with an appropriate bright source from 400 THz (1 THz = 10^12 HZ. As the frequency goes up, the perceived color slowly changes from red to orange to yellow to green to blue and violet. Our eyes don’t perceive violet so well. Typically, it’s darker than other sources at equal intensity. At around 700 THz and 800 THz, the world goes darker again. In short, it isn’t that simple to determine the exact wavelength of color first.


Wavelengths determine the color of light emitted by the LED products. However, every wavelength range is made from a particular semiconductor material family, and the manufacturer doesn’t matter.  Meaning it’s possible to customize the color of your choice to meet the specific wavelength specification needed for traditional bulb light sources like automotive lamps and traffic. 

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