Near-infrared and mid-infrared semiconductor broadband light emitters

Broadband semiconductor sources are ideal and vital light sources for optical coherence tomography systems. Achieving broadband light sources in the near-infrared simultaneously with high spectral bandwidth and output power is still challenging. In the mid-infrared region, it is difficult for quantum cascade materials to obtain desirable broadband light due to the relatively weak amplified spontaneous emission. Chun-Cai Hou of Suzhou Institute of Nano-tech and Nano-bionics and co-workers have developed a 1.2 μm continuous wave operating superluminescence source with simultaneously high light power and wide broadband width. More importantly, the team has first developed a 5 μm continuous wave operating mid-infrared superluminescence source at room temperature by using a quantum cascade active region and a dual-end emitting analogous monolithic integrated tapered waveguide structure. This work will bring a new opportunity towards optical coherence tomography systems.