Ultracompact, 160-Gbit/s transmitter optical subassembly based on 40-Gbit/s×4 monolithically integrated light source

The first ultracompact transmitter optical subassembly for long-distance, beyond-100-Gbit/s data communication systems based on a monolithically integrated light source is developed, and 40-Gbit/s× 4 operation with the clear eye openings up to 10-km single mode fibre transmission is demonstrated.

Introduction

With the rapid growth of data communication services, such as data storage service and cloud computing, there is an urgent and strong demand for more network capacity. These socalled “datacom” services cover distances ranging from a few meters to some tens of kilometers. For relatively long-distance transmission, optical data links are promising and have been intensively studied. For example, in 100-Gbit (100G) Ethernet (100GbE)¹ standardized in 2010, two standards, LR4 and ER4, are defined for transmission distances larger than 100 m. However, since it was difficult to achieve 100-Gbit/s by cost-effective on-off keying format, , a multi-lane LAN-WDM system was employed. For the transmitter side, this means that four 25G light sources and their optical multiplexer (MUX) are required and various light sources have been reported^{2–3 4}, including a compact monolithically integrated light source⁵, ⁶.