What is BS EN IEC 61290‑4‑4 - Optical amplifiers about?
BS EN IEC 61290 is a series on optical amplifiers. An optical amplifier is a device that amplifies an optical signal directly, without the need to first convert it to an electrical signal. BS EN IEC 61290‑4‑4 applies to optical amplifiers (OAs) and optically amplified elementary sub-systems. More specifically, BS EN IEC 61290‑4‑4 applies to OAs using active fibres (optical fibre amplifiers, OFAs) containing rare-earth dopants, such as erbium-doped fibre amplifiers (EDFAs), presently commercially available, as indicated in IEC 61291-1.
BS EN IEC 61290‑4‑4 provides the general background for optical amplifier gain transients and their measurements and indicates those IEC standard test methods for accurate and reliable measurements of the following transient parameters:
- Optical input power increase/decrease transient gain overshoot and transient net gain overshoot
- Optical input power increase/decrease transient gain undershoot and transient net gain undershoot
- Optical input power increase/decrease gain offset
- Optical input power increase/decrease transient gain response constant (settling time)
These parameters have been included to provide a complete description of the transient behaviour of the gain-controlled optical amplifier. The parameters defined in BS EN IEC 61290‑4‑4 are applicable if the amplifier is an OFA or an alternative type of optical amplifier.
Who is BS EN IEC 61290‑4‑4 - Optical amplifiers for?
BS EN IEC 61290‑4‑4 on optical amplifiers is useful for:
- Telecommunication component manufacturers
- Telecommunication equipment manufacturers
- Design engineers
- Quality control personnel
Why should you use BS EN IEC 61290‑4‑4 - Optical amplifiers?
Optical amplifiers are important in optical communication and laser physics. They are used as optical repeaters in the long-distance fibre optic cables which carry much of the world's telecommunication links. When the input power to an optical amplifier operating in saturation changes sharply, the gain of the amplifier will typically exhibit a transient response before settling to the required gain. This response is dictated both by the optical characteristics of the active fibre within the optical amplifier as well as the performance of the gain control mechanism. Definitions are provided in BS EN IEC 61290‑4‑4 that describe a dynamic event leading to transient response. Rise and fall time definitions are shown BS EN IEC 61290‑4‑4.
The terms generally used to characterize the transient gain behaviour of a gain-controlled optical amplifier for the case of optical input power decrease are defined in BS EN IEC 61290‑4‑4. The figure specifically represents the dependence of the gain of optical signal when optical input power is decreased. Likewise, the transient gain behaviour for the case when optical input power is increased is shown BS EN IEC 61290‑4‑4. The main transient parameters are transient gain response time constant (settling time), gain offset, transient net gain overshoot and transient gain net undershoot. The transient gain overshoot and undershoot are particularly critical to carriers and network equipment manufacturers (NEMs), given that the speed and amplitude of gain fluctuations compound through the network as the optical signal passes through an increasing number of cascaded amplifiers. Optical amplifiers typically have very small values for these transient parameters. Using BS EN IEC 61290‑4‑4 you can understand optical amplifiers and optically amplified elementary sub-systems.