Small-signal frequency response of long-wavelength vertical-cavity lasers

The small-signal frequency response of long-wavelength vertical-cavity lasers (LW-VCLs) is of interest in determining the ultimate bandwidth of these devices for use in terrestrial networks. This letter analyses two distinct device structures of double wafer-bonded vertical-cavity lasers operating at 1.5 μm and compares their high-speed performance. We demonstrate the highest modulation bandwidth and the highest modulation current efficiency of an electrically pumped LW-VCL of 7 and 4.1 GHz//spl radic/mA, respectively.