Universal Microelectronics Co., Ltd.

High-speed vertical-cavity surface-emitting lasers (VCSELs) with high single-mode (SM) output power and strong immunity to optical feedback play a vital role in further improving the package d. in co-packaged optics (CPO) systems.Here, by optimizing the structure of VCSEL cavities with Zn-diffusion apertures inside, we can simultaneously improve the SM output power and speed of 850 nm VCSELs.With this novel structure we can achieve a record-high SM output power of 16 mW and a wide 3-dB elec.-to-optical (E-O) bandwidth of 18 GHz.Furthermore, excellent VCSEL performance can be obtained by varying the aperture size for high-speed operations, such as wide E-O bandwidth (27 GHz), high SM power (6.7 mW), low-RIN (-137 dB/Hz), and invariant 56 Gbps eye patterns under strong optical feedback (-6 dB).Error-free transmission can be achieved at around 48 Gbit/s through 500 and 200 m multi-mode and single-mode fibers, resp., without the use of equalizers in the transmission channels.