Visible vs Invisible LED Lights | What They Are & How They Work

Visible vs Invisible LED Lights | What They Are & How They Work

LEDs emit a light spectrum that is quite similar to sunlight. In fact, LEDs can emit both visible and invisible light, plus they can mimic the hue and natural intensity of the sunlight.

The lighting industry and LED manufacturers like LIGITEK Electronics, have taken full advantage of the potential of LEDs and applied it to various everyday life uses. Whether you know it or not, you come in contact with light-emitting diodes everyday.

For instance, smart LED TV, remote controls, and even LIGITEK UV-C water purifiers use LED components for their operation. Besides everyday living applications, LEDs are also used in disinfection of medical equipment and food.

In spite of these, the truth is visible and invisible light holds great potential for a variety of industries. Let’s look at some facts about LED lights and how they work.



What Are Visible LED Lights?

In simple terms, visible light is a wavelength that the human eyes can see. It is a form of electromagnetic (EM) radiation and falls between the infrared (IR) and Ultraviolet (UV) spectrum. Other examples of EM radiation include radio waves, infrared radiation, X-rays, microwaves, and UV radiation. 

Visible light is produced by anything that gives out light or glows. This could be natural sources like the sun, fire, and candles, or artificial sources like the TV, light bulbs, and glow sticks.

When current passes through an LED, it emits visible light. However, the color of this light depends on 2 factors. Firstly, the band gap of  the semiconductor material used when manufacturing the LED. 

Secondly, various wavelengths of light can be produced by LEDs by simply varying the organic (as in OLEDs) and inorganic materials used in the production of the LED. These are the major factors that determine the dominant wavelength.



How Do LEDs Emit Visible Light?

Light-emitting diodes, (LEDs), like other types of diodes, allow current to flow in one direction while opposing their flow to the opposite direction. As mentioned earlier, LEDs emit light when current passes through them. Now, here is how it works.

Basically, LEDs are like small molecular light engines that require electrons to run. As electrical current passes through it, electrons recombine with holes in the semiconductor material.

When an electron falls into these holes, it loses its energy which gets released as photons. In the process, electromagnetic radiation is emitted giving off visible light spectrum.

The EM radiation emitted is called Electroluminescence.

You know the rest. Somewhere between the EM radiation is the visible light spectrum we all see. The common LED lights that are visible are red, blue, green, yellow, white and amber.

Applications of Visible Light

Manufacturers of LED products including LIGITEK Electronics, have fully exploited the potentials of visible LED lights. Here are some applications of visible light.

  • Applied in the manufacture of laser lights for surgery
  • Used as part of LED display panels for TV
  • Incorporated in making LED boards for digital signs
  • As component of MRI scanners
  • Mobile phones and computers use them



What Are Invisible LED Lights?

Invisible LED lights are simply wavelengths in the electromagnetic spectrum that are too short or too long to be detected by the human eye. Remember those photons that are emitted when current passes through LEDs? The EM radiation they give off also has an invisible light spectrum.

Furthermore, invisible lights are broadly categorized into two depending on their wavelengths. UV rays with wavelengths shorter than visible light, and infrared rays with wavelengths longer than visible lights. 

For centuries, UV and infrared radiation has been used for various sterilization and medical processes. However, in the same way LEDs have replaced light bulbs and other light sources, they are now replacing UVs and infrareds.

So, what is the application of LEDs that emit invisible infrared light? You can read this article to understand how LIGITEK UV-C LEDs are used for sterilisation and disinfection.



Applications of IR LEDs

IR LED or Infrared Light Emitting Diode, is a device which emits light in the  infrared range of the EM radiation spectrum. This SSL (Solid State Lighting) device allows for efficient production of infrared light.

Without a doubt, IR LED has a lot of useful applications in electronic devices and circuits. The most common use is in remote controls of televisions and other electronic devices.

Furthermore,  IR LEDs can be used with various types of sensors and are now becoming a common component in machine-to-machine (M2M) and Internet of Things (IoT) applications.

Here are some other applications and uses of IR LEDs.

  • Used as heat-sensitive thermal imaging camera. It can be applied in a variety of medical equipment to check the body’s heat pattern.
  • Used as night vision enhancers. It can be applied to video and image cameras to amplify light. Often used by the military and security personnels.
  • Used to track objects. It can be applied in missile technolgy for monitoring and tracking.
  • Satellites make use of IR LEDs to track weather changes and determine water temperature. It can also be applied in optical space communication systems.
  • Used in digital photography, door phone, monitoring system, and in theftproof alarms.
  • IR LEDs are used as card and paper tape readers.
  • Can be used as a shift encoder.
  • Game consoles gesture recognition
  • ANPR, CCTV surveillance
  • Traffic control and safety



What Devices Use Infrared Light?

A number of devices use IR-LED as part of their components. Some of these devices are;

  • Game consoles
  • Safety light curtains
  • Parking sensors
  • Door control and CCTV
  • Biometrics devices
  • Touch screens
  • Remote controls
  • Security cameras



Examples of LIGITEK Invisible LED Products

LIGITEK invisible LEDs have been used in a lot of electronic circuits and devices. The company’s broad portfolio of LED products features high-quality designs and next-gen innovations. Here are some examples of invisible LED products manufactured by LIGITEK.


Product Categories Featured Products
  • SMD
  • PLCC & High Power
  • Through Hole
  • 3mm
  • 5mm


  • 5mm
  • 9033
  • 3mm

Where To Buy LIGITEK Invisible LED Products

So far, you must agree that LIGITEK has a lot to offer with their myriad of LED products. You can take a closer look at LIGITEK’s flagship LED products to get detailed information about features and sample applications.


To purchase LED lighting components from LIGITEK, you can reach out to BD Electronics, their official European distributor. Yo can also browse our online store for a better presentation of LIGITEK’s LED products.

If you want to find more new about electronic components, please check out the following articles:

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