Recovering a rare-earth-doped optical fiber under irradiation
An optical fiber apparatus and a method of recovering radiation-induced-attenuation (RIA) onto a rare-earth-doped optical fiber under irradiation are provided in this disclosure. A light source is coupled to a rare-earth doped optical fiber. The light source emits a combination of mode locked pulsed light and non-mode locked quasi-continuous-wave light. The mode locked pulsed light are used to recover RIA onto the rare-earth doped optical fiber in real time, and the non-mode locked light are used to pump the rare-earth doped optical fiber as a gain medium. Each pulsed duration of the mode locked pulsed light is much shorter than operation duration of the non-mode locked light, such that an instantaneous power of the mode locked pulsed light exceeds a saturated pumping power required for the rare-earth doped optical fiber, so as to effectively elevate the core temperature of rare-earth doped fiber to achieve a confined photo-annealed recovery of RIA onto rare-earth doped fibers.
1. An optical fiber apparatus, comprising:
an optical fiber assembly comprising at least a rare-earth doped optical fiber; and
a light source, coupled to the optical fiber assembly, for emitting a combination of mode locked pulsed light and non-mode locked quasi-continuous-wave light, wherein the mode locked pulsed light raises a core temperature of the rare-earth doped optical fiber to a temperature of at least 300° C. to recover radiation-induced-attenuation (RIA) onto the rare-earth doped optical fiber in real time, the non-mode locked light are used to pump the rare-earth doped optical fiber, and pulsed durations of the mode locked pulsed light are shorter than operation durations of the non-mode locked quasi-continuous-wave light.
2. The optical fiber apparatus of claim 1 , wherein the light source is a laser or a broadband light source.
3. The optical fiber apparatus of claim 1 , wherein a wavelength of the mode locked pulsed light and the non-mode locked quasi-continuous-wave light is 550-1200 nm.
4. The optical fiber apparatus of claim 1 , wherein the light source is an optical amplifying light source for exciting rare-earth doped optical fiber.
5. The optical fiber apparatus of claim 1 , wherein the light source is a photo-annealing light source.
6. The optical fiber apparatus of claim 1 , wherein an instantaneous power of the mode locked pulsed light exceeds a saturated pumping power required for the rare-earth doped optical fiber, such that an output light power from the rare-earth doped optical fiber is insensitive to the variation of the mode-lock pulse duration.
7. The optical fiber apparatus of claim 1 , wherein the mode locked pulsed light recover at least 50% of the RIA onto the rare-earth doped optical fiber.
8. The optical fiber apparatus of claim 1 , wherein the mode locked pulsed light recover the RIA on the rare-earth doped optical fiber at least partially in a range of 400-2000 nm.
9. A method of recovering radiation-induced-attenuation (RIA) onto a rare-earth-doped optical fiber under irradiation, the method comprising:
coupling a light source to a rare-earth doped optical fiber; and
emitting a combination of mode locked pulsed light and non-mode locked quasi-continuous-wave light by the light source, wherein the mode locked pulsed light raises a core temperature of the rare-earth doped optical fiber to a temperature of at least 300° C. to recover RIA onto the rare-earth doped optical fiber in real time, and the non-mode locked light are used to pump the rare-earth doped optical fiber.
10. The method of claim 9 , wherein pulsed durations of the mode locked pulsed light are shorter than operation durations of the non-mode locked quasi-continuous-wave light.
11. The method of claim 9 , wherein the light source is a laser or a broadband light source.
12. The method of claim 9 , wherein a wavelength of the mode locked pulsed light and the non-mode locked quasi-continuous-wave light is 550-1200 nm.
13. The method of claim 9 , wherein an instantaneous power of the mode locked pulsed light exceeds a saturated pumping power required for the rare-earth doped optical fiber, such that an output light power from the rare-earth doped optical fiber is insensitive to the variation of the mode-lock pulse duration.
14. The method of claim 9 , wherein the mode locked pulsed light recover at least 50% of the RIA onto the rare-earth doped optical fiber.
15. The method of claim 9 , wherein the mode locked pulsed light recover the RIA onto the rare-earth doped optical fiber at least partially in a range of 400-2000 nm.