For which wavelengths should optical power meters be calibrated when testing fiber-to-the-user (FTTx) installations?

The correct choice, which includes 1,490 nm, 1,550 nm, and 1,577 nm, aligns with the typical wavelengths used in fiber-to-the-user (FTTx) installations.

In FTTx deployments, these wavelengths are significant for various applications such as passive optical networks (PON) or in point-to-point configurations. Each of these wavelengths serves specific purposes. For instance, 1,550 nm is widely used for long-haul transmission due to its lower attenuation in standard glass fibers, making it optimal for high-capacity data transmission over long distances. The 1,490 nm wavelength is often utilized for upstream signals, while 1,577 nm can be used in some PON configurations for downstream signals.

These wavelengths cover the essential operating bands for the systems most commonly deployed in FTTx networks, allowing for effective testing and performance verification of the optical power being transmitted through these fiber connections.

Calibration at these specified wavelengths ensures that the optical power meters provide accurate readings, which is critical in troubleshooting and maintaining the integrity and performance of the fiber optic network.