Passive DPSK demodulator: To avoid system control involving complicated feedback algorithm and power consumption, a passive DPSK demodulator can be built. As indicated by its name, a passive DPSK demodulator does not have the tuning capability and its phase, or spectral constructive/destructive peaks, is fixed when it is built. By “passive” it means that the DPSK demodulator does not contain spectral tuning element in the device.
Semi-tunable DPSK demodulator: Considering the contribution of TDFS to the channel misalignment and that TDFS does not scale down with FSR as does the FSR-error, the passive solution will not work well for a low-bit-rate system. However, by combining the features of tunable and passive DPSK demodulators, Optoplex developed semi-tunable DPSK demodulator, also known as Colorless DPSK Demodulator. A colorless DPSK demodulator is a special tunable DPSK demodulator whose optical performance is the same as passive DPSK demodulator, but, like a tunable DPSK demodulator, equipped with a tuner for providing a few GHz tuning capability. Its FSR can be either 25 GHz or 50 GHz so that it can be used in systems with channel spacing being a multiple of the FSR. As a result, Optoplex’s colorless DPSK demodulator combines the advantages of both tunable and passive DPSK demodulators and can serve the ever-demanding needs of system providers.
Dual-Rate DPSK Demodulator is also available. For DQPSK demodulator, please visit DQPSK demodulator page.
September 21, 2011