L-Band Wavelength-Tunable Er³⁺-Doped Tellurite Fiber Lasers

Er‐Activated Hybridized Glass Fiber for Laser and Sensor in the Extended Wavebands

“…To maintain the compactness of the all‐fiber configuration, several FBGs with the reflective wavelengths of 1609, 1615.0, 1620.6, 1626.6, and 1630.0 nm are employed to replace the diffraction grating. [ 5a ]…”

“…[ 4 ] Even for the wavelength of more than 1620 nm, rather few researches have previously been realized. [ 5 ] Using Er‐doped tellurite glass fiber, the fiber laser with wavelength tunable range of 1589–1627 nm has been realized by Fu et al. [ 5a ] However, the poor mechanical properties (rather fragile) and the difficulty in splicing of the tellurite fiber poses extraordinary difficulty for practical applications.…”

“…[ 5 ] Using Er‐doped tellurite glass fiber, the fiber laser with wavelength tunable range of 1589–1627 nm has been realized by Fu et al. [ 5a ] However, the poor mechanical properties (rather fragile) and the difficulty in splicing of the tellurite fiber poses extraordinary difficulty for practical applications. By employed a piece of Er‐Yb codoped phosphor‐silicate fiber, Laroche et al.…”

“…By employed a piece of Er‐Yb codoped phosphor‐silicate fiber, Laroche et al. [ 5b ] have obtained a laser at 1627 nm in a double‐cladding fiber laser, but the output beam behaves multimode operation as result of the large core diameter of the fiber of 24 µm. These sources have demonstrated the advantages of the lasing at long‐wavelengths.…”

“…Moreover, the signal‐to‐noise rate of the optical spectrum is considerably low, when one considering the laser at 1627 nm with a SNR of only 15 dB. [ 5c ] Thus, the challenge of Er‐activated fiber laser in U‐band has been met with limited success since the invention of the first Er‐activated fiber laser in the mid‐1960s. [ 6 ]…”