Two-color experiments with infrared lasers

Various pump–probe application experiments that can be done with infrared FELs and with table-top lasers are described. The spectral ranges that can be reached with these lasers and their spectral width and pulse length are briefly discussed. Many interesting experiments can be performed by using different wavelengths either with a two-color FEL or with various lasers synchronized with an FEL. A few examples are given.