We report on the fabrication of photonic band gap fiber made of multicomponent glass. This fiber has a hexagonal lattice made of an array of 17 x 17 air capillaries with a lattice constant Λ=6.0 μm and air holes of diameter equal to d=5.7 μm. A hollow core is created by omitting seven central microcapillaries and have diameter of 16 μm. Characterization results show that the fiber can guide the light in the visible range with a central wavelength of 510 nm. The transmission properties for the presented PCFs are measured by using a broadband light source and an optical spectrum analyzer. In the paper we discuss also possible future modifications of the structures and their potential applications.
Most works on photonic crystal fibers with a photonic bandgap are concerned with structures made of silica glass with a hexagonal lattice. However, there are many other possible choices for the crystal structure of the fiber. In this paper, we study the optical properties of photonic bandgaps in a hollow-core photonic crystal fiber with a square lattice fabricated from multi-component glass. A composition of oxides was chosen to obtain a refractive index contrast higher than in fused silica fibers. The core size of the fiber is 11 microns and the cladding is made of an array of 17 x 17 air capillaries. A full-vector mode solver using the biorthonormal basis method is employed to analyze the modal properties of the fiber. We verify the guiding properties of the fiber by FDTD simulations. The transmission properties for several lengths of the fiber were measured by using broadband light from a nanosecond-pulse supercontinuum source and an optical spectrum analyzer. Preliminary results show that light is guided around 1650 nm. Possible modifications of the structure and potential applications will be discussed.
Recently emerged photonic bandgap fibers with their extraordinary optical properties offer many interesting device applications. We present the status of our work on the use of this kind of a fiber in sensing and wavelength referencing both in the 1300 and 1500 nm wavelength regions. The photonic bandgap fibers are spliced to standard single-mode fibers at input end for easy coupling and filled with gas through the other end placed in a vacuum chamber. The technique is applied to measure absorption lines of strongly absorbing gases such as acetylene and hydrogen cyanide by employing tunable lasers and LEDs as light sources. The measurement of weakly absorbing gases such as methane and ammonia is also explored. To realize a permanent wavelength reference sealing of a photonic bandgap fiber using index-matching UV-curable adhesive is demonstrated.