System for generating Raman vibrational analysis signals

A system for generating optical signals for Raman vibrational analysis of an external specimen, the system comprising:

• a laser source capable of emitting at least one femtosecond fundamental optical pulse in a first band of fundamental frequencies comprising at least one first (ωf1) and one second (ωf2) fundamental frequencies;
• a second-harmonic generating system comprising at least one nonlinear optical crystal capable of converting said at least one fundamental optical pulse into at least two second-harmonic optical pulses having a narrower band with respect to the bandwidth of the at least one fundamental pulse, a first second-harmonic pulse at a first second-harmonic frequency (ωp) of the first fundamental frequency (ωf1) and a second second-harmonic pulse at a second second-harmonic frequency (ωs) of the second fundamental frequency (ωf2), said second second-harmonic frequency being different from the first second-harmonic frequency, and
• a Raman vibrational analysis apparatus capable of receiving said first and second second-harmonic pulses and of directing them toward said specimen.