Compact Flip-Chip Interconnection 112-Gbit/s EADFB Laser Array Module With High Eye-Mask Margin

The first compact and high-performance optical transmitter using flip-chip interconnects has been developed for a 112-Gbit/s transceiver. The flip-chip interconnects provide lower crosstalk and a higher modulation bandwidth than wire interconnects. The flip-chip interconnection module has 3-dB frequency bandwidths of over 30 GHz. This value is up to 5 GHz better than that of a wire interconnection module. Under four-channel simultaneous operation, the OTU4 mask margins for all four lanes of the flip-chip interconnection module exceed 37%. These values are degraded up to only 4% compared with those for single-channel operation. In addition, an error-free transmission through 10 km of single-mode fiber at 112 Gbit/s is demonstrated.

I. Introduction

With the rapid growth of internet traffic, we need to increase the throughput of optical communication networks. 100-Gbit/s Ethernet [1] and the Optical-channel Transport Unit (OTU4) [2] have been standardized to meet this demand. For long reach applications over single-mode fiber (SMF), 800-GHz LAN-WDM using four 25.78-/27.95-Gbit/s optical signals in the 1.3-μm band was adopted. For 100-/112-Gbit/s applications, a centum form-factor pluggable (CFP) [3] transceiver was defined in the CFP Multi-Source Agreement (MSA). The current CFP transceivers consist of many discrete components. For example, their transmitter section consists of four electroabsorption modulators integrated with DFB laser (EADFB laser) modules [4]–[9] and an optical multiplexer (MUX). Therefore, the size of the CFP transceiver is rather large and requires downsizing. CFP2 and CFP4 have been under discussion in relation to the CFP MSA as small and cost effective next-generation 100-/112-Gbit/s transceivers.