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-gr oove AlGaAs-GaAs quantum-wire (QWR) laser are investigated, At short cavity lasers less than 300-mu m, a discrete wavelength switching from the first (n = 1; 837.7 nm for the 800-mu m cavity) to the second (n = 2; 826.5 nm fo r the 220-mu m cavity) subbands occurs due to the increased threshold gain, resulting from the increased cavity loss. Utilizing this characteristic, u ltrafast lasing behaviors at the n = 1 and n = 2 quantized transitions of t he QWR, generated by the gain-switching method, are demonstrated and compar ed.