This paper presents the development of an automatic alignment system for specialty optical fibers. Based on a XY
coordinates system, the alignment is achieved by the control of stepping motors through displacement algorithms. A
hexagonal shape arrangement of SMF´s fibers generates a map location of the spot light. This photo-detection system
enables to analyze the launching of the beam into the fiber. Through an USB based PC interface and software to
automate the alignment process the device's performance has been improved in time and in optical coupling efficiency.
The results obtained are 2 or 3 seconds in the alignment process and roughly 80% coupling efficiency.
We report for the first time, a single mode, tunable, double-clad ytterbium-fiber (YDF) laser emitting in a
wavelength range between 976 and 985 nm that operates using the re-imaging effect that occurs in multimode
interference (MMI) devices. The system consists of an YDF with bare fiber cleaved ends. The forward end of this fiber is
fusion spliced to a piece of 3 m of Samarium-doped- single-mode fiber with absorption measured at 980 nm of 0.3 dB/m,
and at 1030 nm of 6 dB/m. The other end of the Sm+3 doped single-mode fiber is spliced to a 16.2 mm long multimode
fiber (MMF) in order to induce the MMI self-imaging effect. From simulations, we found that, at this particular length,
for the MMF, the light exiting will exhibit a maximum transmission for the 980 nm wavelength, while keeping a
minimum for the 1030 nm wavelength. Near to the MMF facet, at a distance between 0 and 100 µm, we place a dichroic
mirror which also helps in the selection of the wavelength emission. We calculated that 10 dB gain generated at 980 nm
is enough to build up a laser since the total round-trip cavity losses are estimated to be 8.8 dB, whereas for the unwanted
1030nm get more than 60dB insertion loss in this setup. At the end, there is more than 1 dB for the effective gain at the
preferred wavelength emission range which is enough to promote lasing at around 980 nm.
An optical pumping device consisting of pigtailed diode lasers and a paraboloidal mirror is presented. The pigtailed diode lasers are mounted on a circular plate in radial position in front of the mirror, and the reflected beams are then launched into a 200-µm-diam undoped silica fiber with silicone cladding, with up to 75% coupling efficiency. The implementation of the device is simple and can be used to scale the power in fiber laser systems.
In this work, we propose a set of photonics devices that can be employed as part of optical communications systems.
These devices consist of an isolator, a circulator, a multiplexer and a pump concentrator, and are based on the
functionality of an optical paraboloidal mirror. The devices were first studied using software for optical modeling and
then were experimentally tested. For the cases of the isolator and the circulator, we obtained numerically roughly 50 dB
of isolation. Furthermore, we proposed a simple and a novel multi channel multiplexing device, and finally, we asses the
alternative and elegant way of the combination of high power multimode diode laser to increase the power capability of
diode laser systems that are commonly used in high power fiber laser. In all the cases, the design showed the advantage
of the easiness of alignment and the simplicity to implement.