Infrared degenerate four-wave mixing imaging using infrared to visible up-conversion

Summary form only given. Degenerate four-wave mixing (DFWM) spectroscopy has been used for imaging the distribution of species in flame and other chemical environments. DFWM produces a coherent signal, which permits remote detection and easy elimination of background noise. In recent years, there is a considerable interest in an infrared DFWM (IR-DFWM), because most molecules have transitions in the IR region. However two-dimensional imaging in IR has not been well developed, partly due to the lack of sensitive imaging devices. To overcome the above problem we have proposed a new imaging scheme, where the IR-DFWM signal is up-converted to the visible region using nonlinear frequency mixing and detected by an imaged-intensified CCD camera. Since the DFWM generates a coherent signal, it is suited for the upconversion process.