Dual section quantum cascade lasers with wide electrical tuning

This paper describes our development efforts at Northwestern University regarding dual-section sampled grating distributed feedback (SGDFB) QCLs. These devices are the same size, but have much wider electrical tuning, than a traditional DFB laser. In this paper, I will show how we have dramatically extended the monolithic tuning range of high power quantum cascade lasers with high side mode suppression. This includes individual laser element tuning of up to 50 cm -1 and 24 dB average side mode suppression. These lasers are capable of room temperature continuous operation with high power (<100 mW) output. Additionally, we have demonstrated a broad spectral coverage of over 350 cm -1 on a single chip, which is equivalent to 87.5% of the gain bandwidth. The eventual goal is to realize an extended array of such laser modules in order to continuously cover a similar or broader spectral range, similar to an external cavity device without any external components.