Spectroscopic chemical sensing based on semiconductor lasers is already an established method for highly sensitive and selective detection. However, most semiconductor lasers have a rather narrow tuning range (< 1 %) which limits the detectable molecular species. A common solution to this problem is to use external cavity lasers (tuning range > 10 %) which allow for broadband and multi-species detection at the cost of reduced tuning speed, decrease in robustness, and generally higher cost. A particularly elegant way to perform a broadband and high resolution spectroscopic detection is the dual-comb spectroscopy technique . This field has recently received some attention due to the possibility of replacing the mode-locked frequency combs with multi-mode Fabry-Perot (FP) semiconductor lasers to enable robust and cost efficient design.
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