The Way of Testing A Fiber Optic Transceiver
Author:Utoptical Date: 10/25/2018
The Way of Testing A Fiber Optic Transceiver
Optical transceiver was first expanded, establishing the performance of it was outspoken. The complete network was authorized and owned by a single company, and if the system worked, thorough testing of the sub components was irrelevant Today, most optical networks use components that may come from different suppliers. Hence, to examine the adaptability of each fiber optic transceiver becomes especially significant ,This article will focus on the way of testing a fiber optic transceiver.
How to test a fiber optic transceiver?
A fiber optical transceiver consists of a receiver and the transmitter. A low-quality transmitter can recoup by a low-quality receiver. You need to check the specifications and it needs to be assured that any receiver will inter operate with a worst-case transmitter, and any transmitter will inter operate with a worst-case receiver and provide a signal with to quality.
There are two steps to examine a transmitter
The input signal used to test the transmitter must be good enough. Measurements of jitter and an eye mask test must be performed to confirm the quality using electrical measurements. An eye mask test is a common method to view the transmitter waveform and present a vast quantity of information about overall transmitter performance.The optical output of the transmitter must be examined using several optical quality metrics such as an OMA(optical modulation amplitude mask test. and Extinction Ratio.
There are two steps to examine receiver :
One must ensure that the input signal is of good enough quality, testing the receiver associated with sending a signal that is of poor enough quality. To do this, a stressed eye depicting the worst case signal shall be created. This is an optical signal, which needs to be calibrated using jitter and optical power measurement.
Finally, testing the electrical output of the receiver must be performed. Three basic categories of tests must be performed:
● A mask test, which ensures a large enough eye opening. The mask test is usually accompanied by a BER (bit error ratio) depth.Receiver Testing
● Jitter budget test, which tests for the amount of certain types of jitter.
● Jitter tracking and tolerance, which tests the ability of the internal clock recovery circuit to track jitter within its loop bandwidth.
As systems became more complex, faster, and even cheaper, it became necessary to test receivers using non ideal signals with different types of impairments. This is commonly referred to as a stressed signal. The first types of stressed signals that gained wide acceptance in high-speed fiber-optic communications were for long-haul applications where the use of Erbium Doped Fiber Amplifiers was common. The Amplified Spontaneous Emission (ASE) noise could cause excess errors on receivers that otherwise performed well when tested under typical ideal conditions. Vendors of long-haul network equipment required test signals intentionally degraded by ASE noise. These tests still are in wide use today.
As the use of inexpensive high-speed data links increased, cost requirements demanded interchangeable components. The philosophy for high-speed optical communications testing was changed significantly by the 1- and 10-Gigabit/s Ethernet standards. IEEE 802.3z (1Gb/s) published in 1998 and IEEE 802.3ae (10Gb/s) published in 2002 introduced receiver testing with degraded signals. Both standards dictate a well-defined combination of impairments that shall be added to an ideal signal presented to the receiver under test. The degradation emulate the worst-case noise and inter symbol interference (ISI) that might occur in a system. This approach to real-world testing can be considered as the evolutionary portion of these standards.
The receiver must properly recover signals that are degraded by expected worst-case performance of the transmitter and fiber. For example, 802.3ae specifies a test signal with both amplitude and timing impairments. The degraded signal eye shows closure relative to a clean signal due to intentional timing jitter and amplitude interference. This process was given the name stressed eye testing.
In fiber optic communication network equipment, the fiber optic transceiver is the most basic part. It functions exactly the same as your computer’s Ethernet card. A fiber optic transceiver has two ports: a transmitter port and a receiver port. Utoptical provides all kinds of transceivers, which can be compatible with many brands, such as Cisco, HP, IBM, Arista, Brocade, DELL, Juniper etc. Each fiber optic transceiver has been tested to ensure our customers to receive the optics with superior quality before delivery.
If you are interested in UTOPTICAL full range of optical transceivers & cables ,please visit :UTOPTICAL Online Store.