Patent ID: 11936157
Assignee: POLITECNICO DI MILANO
Field: Measurement (Instruments)
Classification: CPC H  G | IPC G  H

Claim 13:
14. A method of outputting filtered light pulses from a laser device for inducing coherent Raman scattering in a sample, the method comprising:
generating light at respective different ranges of wavelengths with a first optical cavity comprising a first gain medium and a second optical cavity comprising a second gain medium different to the first gain medium, wherein the first gain medium and the second gain medium are each excitable by a pump light source;
synchronizing and mode-locking, with a synchronizer optically coupled to both the first optical cavity and the second optical cavity, the light from the first optical cavity and the second optical cavity;
filtering, with a first optical filter and a second optical filter, the light from the first optical cavity and the second optical cavity respectively;
outputting from the first optical filter first filtered pico-second light pulses at a first predetermined range of wavelengths;
outputting from the second optical filter second filtered pico-second light pulses at a second predetermined range of wavelengths;
amplifying, at a first fiber amplifier doped with the first gain medium, the first optical filter outputted pico-second light pulses;
amplifying, at a second fiber amplifier doped with the second gain medium, the second optical filter outputted pico-second light pulses;
carrying out synchronization and passive mode locking of the light from the first optical cavity and the second optical cavity, using the synchronizer, wherein the synchronizer comprises a saturable absorber;
wherein at least one of the first optical filter or second optical filter is a tunable optical filter,
wherein at least one of the first optical outlet and the second optical outlet are, respectively, coupled to an optical isolator to directionally output the respectively output filtered pico-second light pulses, and
wherein the step of filtering comprises tuning the tunable filter to vary the first predetermined range of wavelengths or the second predetermined range of wavelengths;

collimating the filtered pico-second light pulses; and
combining, using two dichroic mirrors, the collimated pico-second light pulses.