The transistor laser is a relatively new device that is based on the homogeneous integration of a heterojunction bipolar transistor with a laser diode. As such it offers very unique functionality, and the different device dynamics (compared to conventional lasers) offer a number of benefits, included increased modulation bandwidth, reduced chirp, reduced relative intensity noise and the option to both reduce intermodulation distortion and to eliminate the need for monitor photodiodes thorough the use of collector current feedback.
Here we review recent progress in both the fabrication and modelling of this device, and point to its potential applications in a number of areas of microwave photonics, including links and optoelectronic mixing.