DISCOVERY Semiconductors balanced optical receivers, available from Lastek , have been demonstrated to improve link sensitivity by 3dB or more in applications such as DPSK (differential phase shift keying), and DQPSK (differential quadrature phase shift keying).
In DPSK detection the phase of the optical signal is compared with a one bit delayed version of bit stream after passing through an optical interlever.
The advantage versus OOK modulation lies in the 100 per cent duty cycle possible with balanced detection.
Discovery offers two InGaAs balanced receivers with bandwidths of 14 and 20GHz, the models DSCR405 and DSCR405ER respectively.
These are targeted at digital telecommunications markets using 10 and 20Gbps with FEC and RZ formats.