Room temperature, continuous wave operation of distributed feedback quantum cascade lasers with widely spaced operation frequencies

Lasing properties of room temperature, continuous wave operated distributed feedback (DFB) quantum cascade lasers are reported. A bound-to-continuum active region was used to generate a broad gain spectrum. As a result, first-order DFB lasers employing different periods allowed us to achieve single mode continuous wave emission at several wavelengths ranging from 7.7 to 8.3 <i>µ</i>m at a temperature of +30 °C. The frequency span corresponds to 8% of the center frequency.