Multirate Coherent Receiver, C- and L-Band Versions, OIF-DPC-RX Type 2
Finisar’s CPRV2b22A Integrated Coherent Receiver combines polarization beam splitting optics for the signal and local oscillator inputs, two matched optical 90° hybrids with monolithically integrated balanced photodetectors, and four linear trans-impedance amplifiers (TIAs) with differential outputs in a compact surface-mount package. At the signal input there is a monitor photodiode for input signal monitoring, as well as a variable optical attenuator (VOA). The receiver is available in both C- and L-band versions.
The device separates the incoming signal in X and Y polarization channels. Optical 90° hybrids subsequently demodulate the incident signal for each polarization into its in-phase (I) and quadrature (Q) phase channels, relative to an external local oscillator laser source. The phase channels are converted to electrical signals by pairs of balanced photodetectors that are monolithically integrated with the optical 90° hybrids, and subsequently amplified by linear trans-impedance amplifiers (TIAs). The TIAs feature integrated peak detectors and support both manual and automatic gain control.