A system (10; 30; 100) for Raman vibrational analysis of an external specimen, the system comprising: a laser source (11; 33; 101) apt to emit at least one fundamental optical pulse in a first band of fundamental frequencies comprising at least one first (ω f1) and one second (ω f2) fundamental frequencies; a second-harmonic generating system comprising at least one nonlinear optical crystal and apt to convert said at least one fundamental optical pulse (12; 31,32; 102) into at least two second-harmonic optical pulses, a first second-harmonic pulse at a first second-harmonic frequency (ω p) of the first fundamental frequency (ω f1) and a second second-harmonic pulse at a second second-harmonic frequency (ω s) of the second fundamental frequency (ω f2), said second second-harmonic frequency being different from the first second-harmonic frequency; and a Raman vibrational analysis apparatus apt to receive said first and second second-harmonic pulses and to direct them toward said specimen, wherein said vibrational analysis apparatus is a CARS microscope or spectroscope (19; 50; 118) that uses said first second-harmonic optical pulse as a pump signal and said second second-harmonic pulse as a Stokes signal, the system further comprising: an optical power divider device (16; 35; 104) apt to receive said at least one fundamental optical pulse emitted from said laser source and to power divide it into a first and a second fundamental pulse, said first and second fundamental optical pulses propagating along first and second optical paths respectively and impinging upon said second-harmonic generating system, wherein said second-harmonic generating system comprises a first nonlinear optical crystal (13; 37; 106) arranged in the first optical path and apt to generate said first second-harmonic pulse and a second non-linear optical crystal (14; 38; 107) arranged in the second optical path and apt to generate said second second-harmonic pulse, and an optical recombination device (18; 43,45,49; 115) apt to receive said first and second second-harmonic pulses from said first and second optical paths and to combine them into an optical Raman vibration analysis signal (15; 51; 123) to be directed towards said specimen. a laser source (11; 33; 101) apt to emit at least one fundamental optical pulse in a first band of fundamental frequencies comprising at least one first (ω f1) and one second (ω f2) fundamental frequencies; a second-harmonic generating system comprising at least one nonlinear optical crystal and apt to convert said at least one fundamental optical pulse (12; 31,32; 102) into at least two second-harmonic optical pulses, a first second-harmonic pulse at a first second-harmonic frequency (ω p) of the first fundamental frequency (ω f1) and a second second-harmonic pulse at a second second-harmonic frequency (ω s) of the second fundamental frequency (ω f2), said second second-harmonic frequency being different from the first second-harmonic frequency; and a Raman vibrational analysis apparatus apt to receive said first and second second-harmonic pulses and to direct them toward said specimen, wherein said vibrational analysis apparatus is a CARS microscope or spectroscope (19; 50; 118) that uses said first second-harmonic optical pulse as a pump signal and said second second-harmonic pulse as a Stokes signal, the system further comprising: an optical power divider device (16; 35; 104) apt to receive said at least one fundamental optical pulse emitted from said laser source and to power divide it into a first and a second fundamental pulse, said first and second fundamental optical pulses propagating along first and second optical paths respectively and impinging upon said second-harmonic generating system, wherein said second-harmonic generating system comprises a first nonlinear optical crystal (13; 37; 106) arranged in the first optical path and apt to generate said first second-harmonic pulse and a second non-linear optical crystal (14; 38; 107) arranged in the second optical path and apt to generate said second second-harmonic pulse, and an optical recombination device (18; 43,45,49; 115) apt to receive said first and second second-harmonic pulses from said first and second optical paths and to combine them into an optical Raman vibration analysis signal (15; 51; 123) to be directed towards said specimen. an optical power divider device (16; 35; 104) apt to receive said at least one fundamental optical pulse emitted from said laser source and to power divide it into a first and a second fundamental pulse, said first and second fundamental optical pulses propagating along first and second optical paths respectively and impinging upon said second-harmonic generating system, wherein said second-harmonic generating system comprises a first nonlinear optical crystal (13; 37; 106) arranged in the first optical path and apt to generate said first second-harmonic pulse and a second non-linear optical crystal (14; 38; 107) arranged in the second optical path and apt to generate said second second-harmonic pulse, and an optical recombination device (18; 43,45,49; 115) apt to receive said first and second second-harmonic pulses from said first and second optical paths and to combine them into an optical Raman vibration analysis signal (15; 51; 123) to be directed towards said specimen.