GoPhotonics has introduced an expanded range of Polarization Extinction Ratio (PER) Meters, offering advanced solutions for precise polarization characterization, alignment, and testing in fiber optic and photonic systems. The ERM-202 is a rotating-polarizer polarization extinction ratio meter. It is available in single or dual channel versions. As polarization control becomes increasingly critical in high-performance. The ERM-202 is a dual channel polarization extinction ratio (PER) meter specifically designed to simultaneously measure the PER and power ratio of a device with two polarization maintaining (PM) outputs, such as a Y-branch fiber gyro IOC, PM coupler (PMC), or polarization beam splitter (PBS), as. The ERM-202 is a dual channel polarization extinction ratio (PER) meter specifically designed to simultaneously measure the PER and power ratio of a device with two polarization maintaining (PM) outputs, such as a Y-branch fiber gyro IOC, PM coupler (PMC), or polarization beam splitter (PBS), as. Luna's ERM-202 is a single or dual channel polarization extinction ratio (PER) meter.