24-GHz Directly Modulated DFB Laser Modules for Analog Applications

A directly-modulated distributed-feedback laser module has been achieved with a ridge-waveguide laser chip in our laboratory. It is packaged in butterfly housing with a K connector, and the bandwidth of the laser module is up to 24 GHz with in-band flatness of ±3 dB. It shows a high linearity with input 1-dB compression point of higher than 23 dBm and third-order intercept of 32.2 dBm at 24 GHz. Meanwhile, the packaged DFB laser module gives rather low relative intensity noise of less than -150 dB/Hz when the bias current is 75 mA and it can show a great performance in analog optical communication systems.