Hollow fiber ─ ─ allow propagation of light in air

Manufacture
Hollow photonic crystal fiber can be drawn using standard fiber optic equipment to manufacture. First, the accumulation of hundreds of thin-walled capillary tube made of semi-finished products together. Then after a set-clad, brushed, coated polymer, get dimensions and mechanical properties very similar to the standard single-mode optical fiber. Currently, the hollow photonic crystal fiber manufacturing process is moving very quickly, and even can create unlimited length, the same optical properties of the fiber - at least by the fused silica glass made of hollow photonic crystal fiber can achieve such results.http://www.chinaopticcable.com
Because in fact only a very small number of light transmission in glass, so the energy of hollow photonic crystal fiber transmission capacity is much superior to the conventional fiber.
Although the hollow photonic crystal fiber transmission bandwidth largely by the photonic bandgap cladding decision, but the size and shape of the core and hollow solid material around the small changes in the distribution of fiber will significantly change the optical properties. Therefore, the current focus on improving the lot of research work related to optical design and manufacturing processes, it would not be surprised people think.

Loss
The communication band of hollow photonic crystal fiber, for example, low-loss range of approximately 150 nm, center wavelength of 1570 nm (Figure 2). Outside of this range, losses increase rapidly. Minimum loss is 1.7dB/km, it proved to be hollow waveguide can be achieved at present the minimum (Figure 3). In this low-loss optical fiber window there are some high-loss areas. This is from the surface film (so-called surface film is the core of the glass - air interface or near the resonance) the result, in some wavelengths, the surface film out of the normal decay slowly degraded. In the event of degradation of the wavelength position of the interaction of light with the surface to increase dramatically, it will not only lead to increased optical loss will also change the waveguide dispersion characteristics. In practical applications, these features are unfavorable. However, carefully designed core and cladding, a wish to exclude these negative factors.

Optical transmission
Despite the long-distance communications hollow photonic crystal fiber can not challenge the traditional fiber, but in other important applications in several areas, hollow photonic crystal fiber is superior to conventional optical fiber, which is probably the most noteworthy of the laser beam transmission. Compared with the traditional fiber, hollow photonic crystal fiber is an important advantage of high damage threshold. Because in fact only a very small number of light transmission in glass, so the energy of hollow photonic crystal fiber transmission capacity is much superior to the conventional fiber.