Modified grating-based external cavity diode laser for simultaneous dual-wavelengths operation

We have reported a modified V-shaped external cavity, which is constructed around a commercial diode laser operating at a center wavelength of λ=785 nm by adding a new coated glass plate with about 50% reflectivity to the cavity. This allows simultaneous dual-wavelengths operation in the vicinity of Δν_min=0.18 THz to Δν_max=0.22 THz, which can be used as laser source for terahertz generation either for semiconductor devices or nonlinear schemes.