850 nm optical components for 25 Gb/s optical fiber data communication links over 100 m at 85°C

We report on the development of 25Gb/s 850nm VCSEL and PD components for efficient short-reach optical fiber communication systems. VCSELs with the aperture size 6-7μm show the highest -3dB bandwidth (~20GHz) and D-factor (~8Ghz/mA ^1/2). K-factor is less than 0.25ns for VCSEL with 6 μm aperture. Eye diagrams are clearly open at 25C up to 35Gb/s. The dark current of PDs remain below InA at T <; 50°C and below IOnA when T <; 90°C out to -10V. The extracted PD capacity is linearly proportional to the detector area and less than 200tF even for 45μm PD diameter. Due to elimination of contribution of diffusion process and quite small capacitance of the depletion region eye diagrams are opened at 28Gb/s, even for the PDs with the largest active diameters. Using 35μm PD and 6μm VCSEL error-free 25Gb/s optical fiber communication links were tested over lengths of 203m and 103m at 25°C and 85°C, respectively. Received optical power for the lowest BER is at both temperatures smaller than -4dBm. Obtained results indicate that from the speed and power dissipation perspective developed high-speed CSELs and PDs are suitable for applications in the next generation of short-reach multimode optical fiber interconnects.