We review the optical properties of the mixed crystal CdxHg1-xGa2S4, propose three potential applications to which various physical properties can be tailored, and present experimental results of femtosecond optical parametric amplification in the mid IR from 5.5 to 8 mum with 1.25-mum pumping by a 1-kHz Cr:forsterite regenerative amplifier. (C) 2002 Optical Society of America