{"id":32623,"date":"2019-10-31T21:48:03","date_gmt":"2019-10-31T18:48:03","guid":{"rendered":"https:\/\/prohoster.info\/blog\/kogerentnye-cfp-wdm-100g-200g-i-ih-primenenie-v-sistemah-dwdm\/"},"modified":"2019-10-31T21:48:03","modified_gmt":"2019-10-31T18:48:03","slug":"kogerentnye-cfp-wdm-100g-200g-i-ih-primenenie-v-sistemah-dwdm","status":"publish","type":"post","link":"https:\/\/prohoster.info\/en\/blog\/administrirovanie\/kogerentnye-cfp-wdm-100g-200g-i-ih-primenenie-v-sistemah-dwdm","title":{"rendered":"Coherent CFP WDM (100G\/200G) and Their Application in DWDM Systems","gt_translate_keys":[{"key":"rendered","format":"text"}]},"content":{"rendered":"

\"Coherent
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\nThe first press releases regarding the emergence of coherent CFP modules (coherent CFP optical pluggable modules) started appearing about 5-6 years ago. At that time, their use in optical multiplexing systems was a novelty and essentially represented a niche solution. Now, after six years, these modules have firmly entered the telecom world and continue to gain popularity. What types exist, how do they differ, and what solutions based on them are being offered (and of course, pictures under spoilers) \u2014 all this is below. A basic understanding of DWDM systems is required to read the article.
\n<\/a><\/noindex><\/p>\n

A Brief Excursion into the Past. <\/h3>\n

\nHistorically, the first form factor for optical pluggable modules with a transmission speed of 100G was the CFP, which also became the first form factor for CFP-WDM solutions. At that time, there were two market solutions:<\/p>\n

1. CFP from Menara <\/a><\/noindex> (now part of IPG Photonics), allowing the transmission of 4 separate channels of 28Gbps in the standard DWDM frequency grid of 50GHz using pulse modulation. It did not gain significant popularity, although it had interesting potential for building metro networks. We will not discuss such modules further in the article.
\n\"Coherent
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\n2. CFP from the pioneers \u2013 Acacia Press release<\/a><\/noindex>, built on the most advanced technology for coherent detection at that time using DP-QPSK modulation.
\n\"Coherent
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\nWhat was the breakthrough of the modules from Acacia:<\/b> \u2014 it was the first industry module to offer a separate coherent channel of 50GHz 100Gbit DP-QPSK
\n \u2014 fully tunable in C-band<\/p>\n

Before this, similar solutions typically looked as follows: a linear laser was an inseparable element of the board, which had only one connector for the client optical module. It looked something like this:
\n\"Coherent
\nLet me remind you, that was in 2013.<\/p>\n

\nSuch a module replaced the classic linear DWDM interface on a traditional transponder operating in the C-band, which can be amplified, multiplexed, etc.
\nNow, the principles of building coherent networks have become the de facto standard in the industry, and no one is surprised by this, while the density and range of optical multiplexing systems have increased exponentially. <\/p>\n

Module Components<\/h3>\n

\nThe first module (Acacia) was a type of CFP-ACO. Below is a brief overview of how coherent CFP modules differ. However, first, it is necessary to take a slight off-topic and explain a bit about DSP, which is largely the heart of this technology.<\/p>\n

A bit about the module and DSP<\/b>The module generally consists of several components
\n\"Coherent
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    \n
  1. Narrowband tunable laser<\/li>\n
  2. Coherent modulator with dual polarization<\/li>\n
  3. Digital to analog converter (DAC\/ADC) \u2013 A DAC that converts digital signals to optical and back.<\/li>\n
  4. Digital signal processor (DSP) \u2013 recovers useful information from the signal by removing the influences exerted on the useful signal during transmission. In particular:<\/li>\n<\/ol>\n