We review our recent work on Yb-doped and hybridstructured solid photonic bandgap fibers (Yb-HS-SPBGFs) for linearlypolarized fiber lasers oscillating in the small gain wavelength range from 1160 nm to 1200 nm. The stack-and-draw or pit-in-jacket method is employed to fabricate two Yb-HS-SPBGFs. Both of the fiber shows optical filtering property for eliminating ASE in the large gain wavelength ...

Raman amplification of a 49 cm Bismuth oxide (Bi2O3) as a nonlinear gainmedium based erbium doped fiber amplifier (EDFA) is reported in new and compactdesign in near infrared spectral regions. The bismuth glass host provides theopportunity to be doped heavily with erbium ions to allow a compact optical gain fiberamplifier design by using reduced fiber length and the 1480...

Erbium doped fiber amplifiers (EDFA) are most commonly used in optical networks for the most assorted applications. The fast power transient effect of the cascaded erbium-doped fiber amplifiers (EDFA) in 45 channels optical ring network areinvestigated. The result shows, the power transient effect of EDFAs when channels are added and dropped.It is shown that, for low channel-adding/dropping fre...

We present experimental results of SBS suppression in high power, monolithic, Yb-doped fiber amplifiers via phase modulated laser gain competition. To narrow the linewidth, two-tone laser gain competition between broad (1036 nm) and narrow linewidth (1064 nm) laser signals is investigated in conjunction with phase modulation and yields pump limited output powers of 600 W. Here integration of bo...

Figure 1: Laser wavelength dynamics The effect of self-induced laser line sweeping (or self-sweeping) was discovered in ruby laser in 1962 [1]. It was considered as an undesirable effect due to a small sweeping range. In fiber lasers the effect with broad sweeping range (more than 10 nm) was observed almost 50 years later [2]. The self-sweeping effect is caused by the formation of dynamical pha...

A self-calibrating method is described for measuring the radiative quantum efficiency (QE) in doped optical fibers. The method uses an integrating sphere to collect the fluorescence from the fiber, with pump light transmitted through the fiber end serving as a reference. QE measurements for a 780 or 808 nm pump were made on bismuth-doped AlGeP-silica fibers prepared by aerosol deposition. For b...

We present preparation and spectroscopic characterization of the Tm-doped fibers with enhanced 3H4 fluorescence lifetime thanks to codoping with alumina. With the alumina content of 10 mol %, the fluorescence lifetime of 58 s was achieved. Using experimentally obtained fiber characteristics, we used numerical simulations to study and optimize for the first time the thulium-doped fiber amplifie...

Broadband graphene oxide/PVA films were used as saturable absorbers (SAs) for mode locking erbium-doped fiber laser (EDFL) and ytterbium-doped fiber laser (YDFL) at 1.06 μm and 1.55 μm. They provide modulation depths of 3.15% and 6.2% for EDFL and YDFL, respectively. Stable self-starting mode-locked pulses are obtained for both lasers, confirming that the graphene oxide is cost-effective. We ha...

A widely tunable erbium-doped all-fiber laser has been demonstrated. The tunable mechanism is based on a novel tunable filter using multimode interference effects (MMI). The tunable MMI filter was applied to fabricate a tunable erbium-doped fiber laser via a standard ring cavity. A tuning range of 60 nm was obtained, ranging from 1549 nm to 1609 nm, with a signal to noise ratio of 40 dB. The tu...

A multi-wavelength fiber ring laser of tunable channel spacing is proposed by employing an optical variable delay line (OVDL) in a Mach-Zehnder interferometer. Stable lasing is achieved at room temperature with the hybrid gains of a single mode fiber (as the Raman gain medium) and an Erbium-doped fiber (EDF) in a ring structure. The channel spacing of the present multi-wavelength fiber ring las...