What is one of the major advantages of using coherent technique in optical communication?*Increased resistance to fiber impairmentsScalability to higher data rates by using advanced modulation formatsEnhanced spectral efficiencySimplified receiver design

One of the major advantages of using a coherent technique in optical communication is the scalability to higher data rates by using advanced modulation formats.

Here's a step-by-step explanation:

1. Coherent detection in optical communication involves the phase and amplitude of the signal, which allows for the use of advanced modulation formats. These formats can carry more than one bit per symbol, unlike the traditional on-off keying (OOK) format that carries only one bit per symbol.

2. This means that for the same symbol rate (the number of symbols transmitted per second), more data can be transmitted. In other words, the data rate is increased.

3. Therefore, by using coherent techniques and advanced modulation formats, optical communication systems can achieve higher data rates. This is particularly important for meeting the increasing demand for bandwidth in applications such as internet data centers, high-performance computing, and 5G networks.

4. Other advantages of coherent techniques include increased resistance to fiber impairments and enhanced spectral efficiency. However, these techniques typically require more complex receiver designs.