Cost-Effective Half-Duplex Transceivers for Fiber-to-the-Room Network Enabled by Optical Feedback Resistant Single-Mode Lasers

We propose and demonstrate a cost-effective half-duplex transceiver for Fiber-to-the-Room (FTTR) network by using a homemade uncooled and isolator-free distributed feedback (DFB) laser as both receiver (Rx) and transmitter (Tx). AlGaInAs multiple quantum wells (MQWs) and a partially corrugated grating are utilized for uncooled and isolator-free operation of the DFB lasers. Tx/Rx mode switching is implemented by a specially designed complementary metal-oxide-semiconductor (CMOS) chip including biasing circuits, a trans-impedance amplifier (TIA) and a single pole double throw (SPDT) radio frequency (RF) switch. The transceiver can work up to 5 Gbps in both Tx and Rx modes with 17 ns Rx to Tx switching time and 94.4 ns Tx to Rx switching time, respectively. The Tx output optical power of the transceiver is 11 dBm, while the Rx sensitivity is −18 dBm at a bit error rate (BER) of 10⁻³. This integration method proves that the transceiver is a cost-effective high speed light source for the future FTTR network.