Exemplary embodiments provide tunable laser devices, methods for making
the laser devices and methods for tuning the laser devices. The tunable
laser devices can include an optically pumped semiconductor laser
heterostructure, on which a distributed-feedback (DFB) laser grating
having variable grating spacings (or chirps) can be formed. The optically
pumped semiconductor laser heterostructure can be an optically pumped
type-II quantum well laser structure. The emission wavelength of the
tunable laser devices can be tuned by changing positions of the region
illuminated by the pump laser and with respect to the chirped DFB
grating. The disclosed laser devices and methods can provide tunable
laser emission with a combination of narrow linewidth and high output
power that can be used for remote sensing applications and/or
spectroscopic applications across the entire mid infrared (IR) spectral
region.