Raman Fiber Laser

What is Raman fiber laser?

Raman finer laser is an technology to build high power laser sources outside emission window of conventional rare earth doped gain media. Emission bands of conventional ytterbium, erbium, and thulium/holmium-doped fiber lasers are limited to specific wavelength bands. Raman laser is based on Raman gain based on stimulated Raman scattering (SRS), which is available at arbitrary wavelength in the entire transparency window of optical fiber.


Cascaded Raman Fiber Laser

Cascaded Raman conversion is a process in which multiple stages of Raman scattering occur in a fiber. In this process, the first Raman stage converts a pump laser into a Stokes beam, which can then serve as the pump for a second Raman stage. This second stage can then produce a new Stokes beam, which can serve as the pump for a third Raman stage, and so on. Each successive Raman stage produces a new Stokes beam with a longer wavelength than the previous stage. This enables the creation of a cascade of Stokes wavelengths, which can cover a broad spectral range.

Image: Conventional bands of rare-earth doped fiber lasers.
Video: Cascaded Raman Conversion for an Yb pump.

Demonstration of a Widely Tunable Visible Raman Fiber Laser

We build [packaged] Raman fiber laser with high power available at the entire second Near-infrared window. 

We have demonstrated [visible] Raman fiber laser continuously tunable from 530 to 800nm.

Here is an demonstration of a widely tunable visible Raman fiber laser, tunable from 530nm (green) to 800nm (IR). In the demonstration all the visible colors from green to red could be seen.


Raman Fiber 

Raman fiber is a fiber with low effective area, hence high nonlinearity such that it provides high Raman gain. The zero-dispersion wavelength of the fiber is shifted beyond 2µm such that it does not form a supercontinuum.


Image: Raman fiber of a Raman fiber laser

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