Optical channel monitor (OCM) or Optical performance monitor (OPM) has played an important role in optical networks to measure signal quality at optical layer. It is used for managing high capacity dense wavelength division multiplexing (DWDM) optical network and ROADM (reconfigurable optical Add/Drop) systems. OPM involves assessing the quality of data channel by measuring its optical characteristics without directly looking at the individual bit of data. OPM measures channel power, channel wavelength, and optical signal-to-noise ratio (OSNR) for each channel. These fiber-optic components/modules are typically configured at 50 GHz and 100 GHz ITU grids.
GouMax’s OPM consists of a narrow bandpass tunable optical filter, a photodetector and low noise, high-dynamic range electronics, as schematically shown in Figure 1-1. When a multiple-channel optical signal is incident to the tunable filter, it allows a narrow band of input light centered at a given wavelength to pass through the filter. By altering the central wavelength of pass band of the tunable filter through control electronics, the whole input signal can be scanned and spectrum information of incident signal is detected sequentially. The photodetector converts the light passing through the filter into electrical current that is then amplified and digitized. The data processing unit analyzes the data, calculates channel wavelength, power and OSNR, and then outputs to the customers.
The OSA module can be used as a standalone device. GouMax provides control software and GUI for data analysis.
Figure 1: OCM/OPM Monitor (C-band)
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