The integrated DQPSK receiver incorporates an optical phase demodulator (delay-line interferometer or DLI) with 2 pairs of balanced photo-diodes and 2 linear TIAs into a single butterfly package. Compared with the currently available discrete solution in which a separate DLI and a separate receiver are used, the integrated DQPSK receiver eliminates labor intensive fiber routing and coupling (between the DLI and the balanced receiver) as well as the skew control. Moreover, the integrated DQPSK receiver offers a smaller footprint suitable for today’s demanding high speed transponder applications.
The optical phase demodulator is based on Optoplex’s proprietary technology with high tuning speed (up to ms range) to achieve superior optical and thermal performance. Free space optical alignment is employed to couple the optical outputs from the DLI directly into the waveguide-based balanced photodiodes.
Differential TIAs with bandwidth control, AGC, MGC and PLD are used in the integrated receiver. The high speed interface (RF output) is CPW-SMT with pin dimensions compatible with OIF2009.033.05 IA for 100-Gb/s coherent receiver.
The FSR of the DQPSK receivers can be customer specific, such as 21.5, 21.9, 25, or 28GHz, etc. A colorless version with the spectrum peaks aligned to 25-GHz ITU grid is also available upon request.
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