Tuning Extension of a Difference-Frequency Generation up to 100 nm Using V-Shaped External-Cavity for the Pump Laser

In this research, tunability of a commercial diode laser has extended to about more than ± 11 nm using a v-shaped external-cavity fabricated around the laser. although under normal condition it can be tuned up to about ± 4 nm just by changing its temperature and injection current. such modified diode laser has then used in a difference-frequency generation (dfg) experimental setup as pump source in order to continuous tuning of the generated dfg spectrum up to about ± 100 nm from 4.76 ×[(10)]^(-6) m to 4.85 ×[(10)]^(-6) m in the mid-infrared region. an aggas2 crystal is used as nonlinear medium.