Contents I. Introduction
Highly compact and cost-effective optical transceivers for 100-Gbit/s Ethernet (100GbE) are needed to deal with the exponential growth in data traffic generated in telecommunication networks. 100GbE, standardized as IEEE 802.3ba, has a long reach specification for 40-km transmission over single-mode fiber (SMF), namely 100GBASE-ER4, which employs a multi-lane configuration that has four 25.8 Gbit/s lanes with local area network wavelength division multiplexing (LAN-WDM), which is assigned a wavelength channel spacing of 800 GHz in the wavelength band [1]. To further reduce both the size and the power consumption of the 100GbE transceiver, CFP4 has been under discussion in relation to the centum form-factor pluggable (CFP) multisource agreement (MSA) [2]. To obtain a multi-lane transmitter optical sub-assembly (TOSA) for CFP4 that satisfies 100GBASE-ER4, it is important to pursue TOSA miniaturization while realizing an average optical output power (P avg) of over −1.5 dBm at a minimum dynamic extinction ratio (DER) of 8 dB.
