Tailor distributed amplification for fiber sensing

Fiber optic sensing system exploiting in-line high order Raman amplification, comprising:

• a probe source, comprising a probe laser, for generating a probe light including a probe wavelength;
• an optical fiber, into which said probe light is optically coupled;
• a separator, for separating signal light originating in said optical fiber from light coupled into said optical fiber;
• a detector, optically coupled with said separator, for detecting said signal light;
• a processor, coupled with said detector, for analyzing said detected signal light;
• at least one Raman seed laser, for generating a respective Raman seed light including a respective seed wavelength and seed power;
• at least one Raman pump laser, for generating a respective Raman pump light including a respective pump wavelength and pump power;
• and
• at least one coupler, for coupling said at least one Raman pump laser and at least one Raman seed laser to said optical fiber,
• wherein said respective seed wavelength is between said respective pump wavelength and said probe wavelength;
• and
• wherein said respective Raman pump light, said respective Raman seed light and said probe light propagate along said optical fiber to achieve distributed Raman amplification of said signal light produced by said probe light as it propagates along said optical fiber.