Polarization and wavelength stable superfluorescent sources
AssigneeThe Board of Trustees of the Leland Stanford Junior University
InventorsDario G. Flaquier, Michel J.F. Digonnet, H. John Shaw
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Abstract
The instability of the mean wavelength of a superfluorescent fiber source (SFS) is reduced by randomizing the polarization of light from a pump source or by using polarization maintaining components. In one embodiment, the polarization of a pump source is made more random, leading to greater stability of the mean wavelength of the SFS, with an output mean wavelength that is stable to better than 3 ppm for fall rotation of the pump polarization state. In another embodiment, the polarization of optical radiation throughout the device is kept substantially constant by using polarization maintaining fiber and components, thereby leading to enhanced mean wavelength stability of the SFS.
Claims15
A method of generating superfluorescence, comprising:
- providing a laser medium having first and second ends;
- pumping the first end of the medium with optical output from a first optical pump, the output from the first optical pump having a first power and a first polarization;
- pumping the second end of the medium with optical output from a second optical pump, the output from the second optical pump having a second power and a second polarization different from the first polarization;
- producing optical output from the first end of the medium that comprises:
- a first spectral component having a first mean wavelength and a polarization parallel to the first polarization;
- and
- a second spectral component having a second mean wavelength and a polarization orthogonal to the first polarization;
- and
- selecting the first pump power and the second pump power so as to substantially reduce the polarization dependent gain that would be present if the first power were equal to the second power, so that the difference between the mean wavelength of the first spectral component and the mean wavelength of the second spectral component is substantially reduced.
A method of generating superfluorescent output from a superfluorescence source, comprising:
- providing an optical pump which generates optical output;
- directing the optical output into a polarization mixer which generates a first output signal and a second output signal, the two output signals having respective intensities and different polarizations;
- directing the first output signal into a first end of a solid state laser medium;
- directing the second output signal into a second end of the medium;
- and
- producing optical gain in the solid state medium that is substantially independent of polarization to generate optical output from one end of the solid state medium whose mean wavelength is stable against polarization fluctuations in the superfluorescent source.
Dependencies are inferred from the claim text.