  We demonstrate for the first time a mid infrared silicon Raman amplifier.
Amplification of 12 dB is reported for a signal at 3.39 micron wavelength. The
active medium was a 2.5 cm long silicon sample that was pumped with 5ns pulses
at 2.88 micron. The absence of the nonlinear losses which severely limit the
performance of silicon Raman devices in the near infrared combined with
unsurpassed crystal quality, high thermal conductivity render silicon a very
attractive Raman medium. Such a technology can potentially extend silicon
photonics application beyond data communication in the near infrared and into
the mid infrared world of remote sensing, biochemical detection and laser
medicine.
