Mode-locked fibre ring laser stabilization
AssigneeBritish Telecommunications public limited company
InventorXuekang Shan
Life of this patent
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Abstract
A method is described of stabilizing the output of a mode-locked fibre ring laser (1). The fibre constituting the laser (1) includes a dopant in its core. The method comprises the steps of adjusting the length of the ring laser (1) to minimise variations in its cavity length, and hence lock the phase of the laser output pulses with that of its drive source (2), and subjecting a portion (1a) of the fibre of the ring laser (1) to vibrations at a predetermined frequency whose period is less than the dopant ion upper state lifetime.
Claims16
A method of stabilizing the output of a mode-locked fibre ring laser including a dopant in its core, the method comprising the steps of:
- adjusting the length of the ring laser to minimize variations in its cavity length, and hence phase-lock laser output pulses with that of a drive source, and
- subjecting a portion of the fibre of the ring laser to vibrations at a predetermined frequency whose period is less than the dopant ion upper state lifetime.
Apparatus for stabilizing the output of a mode-locked fibre ring laser including a dopant in its core, the apparatus comprising:
- means for adjusting the length of the ring laser to minimize variations in its cavity length, and hence phase-lock the laser output pulses with that of a drive source, and
- means for subjecting a portion of the fibre of the ring laser to vibrations at a predetermined frequency whose period is less than the dopant ion upper state lifetime.
A method of stabilizing a mode locked ring fiber laser that has an optical path which includes an optical fiber with a dopant ion therein excitable to an upper state with a given lifetime in order to render the fiber optically active for laser action, the path being configured in a ring with a path length which is susceptible to change, and drive means operative cyclically to develop laser output pulses with a phase relationship that is dependent on the phase of the drive means, and with a stability dependent on the length of the path, the method including:
- adjusting the length of the path so as to minimize variations in its length and thereby lock the phase of the output pulses to the phase of the drive means;
- and
- subjecting a portion of the ring to vibrations at a frequency whose period is less than the dopant ion upper state lifetime.
A method of stabilizing an harmonically mode locked laser that has an optical path which includes an optically active region for laser action, the path having a length which is susceptible to change, and drive means operative cyclically to promote supermode oscillation and thereby develop laser output pulses from the waveguide path with a phase relationship that is dependent on the phase of operation of the drive means and with a supermode stability dependent on the length of the path, the method including:
- adjusting the length of the path so as to minimize variations in its length and thereby lock the phase of the output pulses to the phase of the drive means;
- and
- subjecting a portion of the optical path to vibrations at a frequency whose period is selected to promote a predetermined supermode and suppress others to stabilize said oscillation.
Dependencies are inferred from the claim text.