Design and performance of a 10-Gbit/s optical transmitter module

A compact 10-Gb/s optical transmitter module with low-chip output was developed by using a monolithically integrated electroabsorption modulator with a DFB (distributed feedback) laser. A novel optical coupling scheme was used which involves a unique optical isolator with a photodiode for output power monitoring, and a thermoelectric cooler mounted in the package to achieve thermally stable module operation. The module can be operated at a bit rate of more than 10 Gb/s at 1.55 μm and shows a high modulated output power of -1 dBm with a low optical coupling loss of 3.2 dB between chip and fiber. Because its wavelength chirping under high-speed modulation is small, this module is promising for multigigabit intensity modulation and direct detection (IM-DD) optical transmission systems