Mid-infrared semiconductor heterostructure lasers for gas sensing applications
An overview of the three competing mid-infrared semiconductor laser approaches, being diode, quantum cascade and interband cascade laser designs, is given. Limiting factors as well as unique possibilities of each approach are discussed. Several designs of distributed feedback structures for single-mode laser operation are presented, which is an important prerequisite for gas-sensing applications. The analysis of current state-of-the-art device data allows suggestions with respect to suitable fields of applications.