What is coherent optics?

Coherent optics is a specific type of laser technology used by service providers to transmit large amounts of information over fiber optic networks. Historically, lasers transmitted information by controlling just the power levels of the signal - high power to transmit a “1” and low power to transmit a “0.” This type of technology - called “direct detect” - is only good for transmitting information up to about 10 gigabits per second. This may seem like a lot but is not nearly enough to cope with the massive amounts of bandwidth required by today’s networks, which often measure in the 100s of terabits of capacity. To overcome the limitations of direct detect technology, the industry developed a technology called coherent optics that is capable of transmitting more information and transmitting over longer distances. Coherent optics technology transmits 1s and 0s by altering the phase of the optical signal rather than the power levels. And while coherent optics is a far more complex technology, it has enabled us to increase the amount of information each laser can transmit over fiber optics by 80 times - from 10 gigabits per second to 800 gigabits per second. And of course, this technology continues to evolve.

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So coherent optics are the optics that use sophisticated methods of laser pulse modulation instead of traditional ones that control only intensity of laser signal ( ON-OFF Keying).