FIELD: optics.
SUBSTANCE: various examples of implementation relate to active optical fibers and devices containing active optical fibers. Active optical fiber section may contain an active core doped with at least one rare-earth element. Active core can have a first refraction index and can be configured to support a single-mode operation of the optical signal. Active optical fiber section may further comprise at least one cladding layer having a second refraction index. Second refractive index may be less than the first refractive index. Birefringence of the active core can be less than 10−5. Also disclosed are fiber lasers and power amplifiers comprising a portion of active optical fiber.
EFFECT: disclosed is an active optical fiber with low birefringence.
12 cl, 17 dwg
