A tunable laser source has a first laser source to generate a low power continuous wave laser light having a wavelength .lamda.1. A second laser source generates a low power continuous wave laser light having a wavelength .lamda.2. A pump laser source generates a high power pulsed laser light having a wavelength .lamda.0. A first optical parametric amplifier (OPA) receives the laser light having a wavelength .lamda.1 and the laser light having a wavelength .lamda.0 and generates a high power pulsed laser light having a wavelength .lamda.1. A second optical parametric amplifier (OPA) receives the laser light having a wavelength .lamda.2 and the laser light having a wavelength .lamda.0 to and generates a high power pulsed laser light having a wavelength .lamda.2. A difference frequency generator (DFG), receives the high power pulsed laser light having a wavelength .lamda.1 and the high power pulsed laser light having a wavelength .lamda.2 and provides a high power pulsed laser light having a wavelength .lamda.3 wherein .lamda.3=.lamda.1*.lamda.2/(.lamda.2-.lamda.1).