Cavity-length-dependent spectral and temporal characteristics of the gain switched V-groove quantum-wire laser

The cavity-length-dependent spectral and temporal characteristics of a V-groove AlGaAs-GaAs quantum-wire (QWR) laser are investigated. At short cavity lasers less than 300-μm, a discrete wavelength switching from the first (n=1; 837.7 nm for the 800-μm cavity) to the second (n=2;826.5 nm for the 220-μm cavity) subbands occurs due to the increased threshold gain, resulting from the increased cavity loss. Utilizing this characteristic, ultrafast lasing behaviors at the n=1 and n=2 quantized transitions of the QWR, generated by the gain-switching method, are demonstrated and compared.