Wavelength Tunable CdSe Nanowire Lasers Based on the Absorption‐Emission‐Absorption Process

Wavelength tunability of lasers is one of the most important parameters for practical applications such as optical communication, environmental monitoring, and spectroscopy analysis. [ 14–18 ] Recently, tunable semiconductor NW and nanoribbon lasers have been realized, using tunable bandgap nanostructures as the composition tunable gain media. [ 19 –26 ] In this approach, alloyed semiconductor NWs with different bandgaps are necessary components for wavelength tuning; a careful composition control is required in order to obtain high crystal quality stoichiometric NWs. [ 27–29 ] Alternatively, the peak wavelength of NW lasers can also be tuned by changing the geometry of the cavity structures, but the tunable range is limited to about 10 nm. [ 7 , 13 ]