With reference to Visible Light Communication (VLC) technology, which of the following statements are correct?

1. VLC uses electromagnetic spectrum wavelengths 375 to 780 nm.

2. VLC is known as long-range optical wireless communication.

3. VLC can transmit large amounts of data faster than Bluetooth.

4. VLC has no electromagnetic interference.

Select the correct answer using the code given below:

The correct answer is 1, 3 and 4 only.

Let us analyze Visible Light Communication (VLC) technology and evaluate each statement step-by-step to understand why this option is correct:

Statement 1: VLC uses electromagnetic spectrum wavelengths 375 to 780 nm.
Visible Light Communication (VLC) utilizes the visible light portion of the electromagnetic spectrum to transmit data. The visible light spectrum roughly spans wavelengths from 375 nm (ultraviolet boundary) to 780 nm (near-infrared boundary). Since VLC operates by modulating light in this visible range (typically using LED bulbs), this statement is scientifically accurate.

Statement 2: VLC is known as long-range optical wireless communication.
This statement is incorrect. VLC is a short-to-medium-range optical wireless communication technology. Because visible light cannot penetrate walls or opaque obstacles and suffers from path loss and beam blockage, its effective range is limited to short distances (typically within a room or up to a few meters), unlike long-range wireless technologies.

Statement 3: VLC can transmit large amounts of data faster than Bluetooth.
This statement is correct. Visible light has a very high bandwidth potential because the visible light spectrum is thousands of times wider than the radio frequency spectrum used by Bluetooth. VLC can achieve data transfer rates in the range of gigabits per second (Gbps), which is significantly faster than standard Bluetooth data transfer rates (typically limited to a few Megabits per second, or Mbps).

Statement 4: VLC has no electromagnetic interference.
This statement is correct. VLC uses light waves rather than radio waves to transmit information. As a result, it does not interfere with, nor is it affected by, electromagnetic radiation in the radio frequency (RF) bands. This makes it ideal for use in electromagnetic-sensitive environments such as aircraft cabins, hospitals, and nuclear power plants where traditional RF communications (like Wi-Fi or Bluetooth) are restricted.

Therefore, statements 1, 3, and 4 are correct, while statement 2 is incorrect.