Characteristics of a Driver Amplifier Integrated 40 Gb/s EML Module

Driver amplifier integrated (DAI) 40 Gb/s electroabsorption modulator-integrated DFB Laser (EML) modules were developed. The selective area growth (SAG) method were first adopted for fabricating 40 Gb/s EML devices and test showed that the measured 3 dB bandwidth of the Electrical-to-Optical (E/O) response reached about 45 GHz, with a return loss (SI 1) of below -10 dB up to 50 GHz for the devices. For this System-on-Package (SoP) module, a right angle bent coplanar waveguide (CPW) was also developed and, consequently, it was possible to achieve a parallel progression of RF and light. The measured S11 and S21 of the right angle bent CPW was maintained below -10 dB up to 35 GHz and -1.4dB up to 40 GHz respectively. The measured S11 of the fabricated DAI 40 Gb/s EML module was maintained below -6 dB up to about 40 GHz and the 3 dB bandwidth of the E/O response reached about 30 GHz under conditions of an operating temp 25degC, modulator bias 1.4 V and an LD current of 40 mA.