Other limitations include: non-linearity at low power levels, and poor responsivity uniformity across the detector area. InGaAs detectors saturate at intermediate levels. They offer generally good performance, but are often very wavelength sensitive around 850 nm. They are only marginally accurate for "1550 nm" testing, due to a combination of temperature and wavelength affecting. This guide compares three core instruments — the OTDR (Optical Time Domain Reflectometer), the optical power meter (used with a light source), and the Visual Fault Locator (VFL) — so you can choose the right method and combine them in a professional workflow. The comparison focuses only on what the. What are Optical Power Meters? An optical power meter (or laser powermeter) is an instrument for the measurement of the optical power (the delivered energy per unit time) in a light beam, for example a laser beam.
