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.