3 results about "Sum-frequency generation" patented technology

Sum-frequency generation (SFG) is a second order nonlinear optical process based on the annihilation of two input photons at angular frequencies ω₁ and ω₂ while, simultaneously, one photon at frequency ω₃ is generated. As with any second order χ⁽²⁾ phenomenon in nonlinear optics, this can only occur under conditions where: the light is interacting with matter, which is asymmetric (for example, surfaces and interfaces); the light has a very high intensity (typically from a pulsed laser).