ABSTRACT
We report on an all-fiber system delivering more than 100 µJ pulses with a top-hat beam output in the few nanoseconds regime at 10 kHz. The linearly polarized flattened beam is obtained thanks to a 3-mm-long single-mode microstructured fiber spliced to the amplifier's output.
ABSTRACT
A new strategy to obtain a single-mode fiber with a flattened intensity profile distribution is presented. It is based on the use of an OVD-made high index ring deposited on a silica rod having a refractive index slightly lower than the silica used for the microstructured cladding. Using this strategy, we realized the first single-mode fiber with a quasi-perfect top-hat intensity profile around 1 µm. Numerical studies clearly demonstrate the advantage of using a core index depression to insure the single-mode operation of the fiber at the working wavelength.
ABSTRACT
We report significant advances in the fabrication of low loss chalcogenide microstructured optical fiber (MOF). This new method, consisting in molding the glass in a silica cast made of capillaries and capillary guides, allows the development of various designs of fibers, such as suspended core, large core or small core MOFs. After removing the cast in a hydrofluoric acid bath, the preform is drawn and the design is controlled using a system applying differential pressure in the holes. Fiber losses, which are the lowest recorded so far for selenium based MOFs, are equal to the material losses, meaning that the process has no effect on the glass quality.
ABSTRACT
We present the first fabrication, to the best of our knowledge, of chalcogenide microstructured optical fibers in Te-As-Se glass, their optical characterization, and numerical simulations in the middle infrared. In a first fiber, numerical simulations exhibit a single-mode behavior at 3.39 and 9.3 microm, in good agreement with experimental near-field captures at 9.3 microm. The second fiber is not monomode between 3.39 and 9.3 microm, but the fundamental losses are 9 dB/m at 3.39 microm and 6 dB/m at 9.3 microm. The experimental mode field diameters are compared to the theoretical ones with a good accordance.
ABSTRACT
We report several small-core chalcogenide microstructured fibers fabricated by the "Stack & Draw" technique from Ge(15)Sb(20)S(65) glass with regular profiles. Mode field diameters and losses have been measured at 1.55 microm. For one of the presented fibers, the pitch is 2.5 microm, three times smaller than that already obtained in our previous work, and the corresponding mode field diameter is now as small as 3.5 microm. This fiber, obtained using a two step "Stack & Draw" technique, is single-mode at 1.55 microm from a practical point of view. We also report the first measurement of the attenuation between 1 and 3.5 microm of a chalcogenide microstructured fiber. Experimental data concerning fiber attenuation and mode field diameter are compared with calculations. Finally, the origin of fiber attenuation and the nonlinearity of the fibers are discussed.
ABSTRACT
We demonstrate the possibility of fabricating an infrared transmitting waveguide by burying fiber in chalcogenide glasses. Two highly mature chalcogenide glasses are used for these experiments. GASIR glass from Umicore IR Glass, Olen, Belgium, with the composition of Ge(22)As(20)Se(58) is used to draw fibers that are then buried in an As(2)S(3) glass substrate. The glasses we used are compatible, and we obtained a high quality interface. We performed a transmission test with a CO(2) laser at 9.3 microm. The potential for extremely low loss planar waveguides is discussed.
