Photonic crystal fibres

The effects of dispersion and birefringence on stellar interferometry will be discussed in Sections 17.2.3 and 17.2.4. New kind of fibres has been design to manage the dispersion properties using a silica / air structure. These fibres, so called Photonic Crystal Fibres, are very promising for many applications (Peyrilloux et al., 2002). 

Figure 3. Photonic Crystal Fibre (PCF). An air hole / silica arrangement allows to manage the dispersion properties.

Benabid, F. Couny, F. Knight, J. C. Birks, T. A. Russell, P. S. J., Compact, stable and efficient all fibre gas cells using hollow core photonic crystal fibres, Nature. 2005, 434,... 

Smith, C., Venkataraman, N., Gallagher, M. et ah. Low-loss hollow-core silica/air photonic crystal fibre. Nature (Land), 424, 657, 2003. 

Sorensen, T. Broeng, J., Bjarklev, A. et ah. Macro-bending loss properties of photonic crystal fibre. Electron. Lett., 37, 287, 2001. 

Gander, M., McBride, R., Jones, J. et al.. Experimental measnrement of group velocity dispersion in photonic crystal fibre. Electron. Lett., 35, 63, 1999. 

Wadsworth, W., Percival, R., Bouwmans, G. et at., High power air-clad photonic crystal fibre laser, Opt. Express, 11, 48, 2003. 

Wadsworth, W., Knight, J., Reeves, W. et al., Yb +-doped photonic crystal fibre laser, Electron. Lett., 36, 1452, 2000. 

Cordeiro CMB, de Matos CJS, dos Santos EM, Bozolan A, Ong JSK, Facincani T, Chesini G, Vaz AR, Brito Cruz CH (2007) Towards practical liquid and gas sensing with photonic crystal fibres side access to the fibre microstructure and single-mode liquid-core fibre. Meas Sci Technol 18 3075-3081... 

A. Bassi, J. Swartling, C. D Andrea, A. Pifferi, A. Torricelli, R. Cubeddu, Time-resolved spectrophotometer for turbid media based on supercontinuum generation in a photonic crystal fibre, Opt. Lett. 29, 2405-2407 (2004)... 

Luminescence differs from chromic effect in that luminescence is not a colour change but emits light. Opticoluminescence is a typical effect encountered in optical fibres. Opticoluminescent fibres have been widely used in textiles for the function of accurately monitoring body and environmental conditions. Recently photonic crystal fibres (PCFs) have been introduced. The cross-section of the PCF contains either periodically arranged micron-scale air voids or a periodic sequence of micron-scale layers of different materials. " PCFs can appear coloured due to optical interference effects in the microstructured regions. 

Peyrilloux, A., Pagnoux, D., Reynaud, F, 2002, Evaluation of photonic crystal fiber potential for fibre linked version of stellar interferometers SPIE 4838, 1334... 

MICRO-OPTICAL COUPLING OF FIBRE AND PHOTONIC CRYSTAL WAVEGUIDE... 

Losses still occur in the fibres developed for commercial use. Nonetheless, these have been reduced to a point where transmission over kilometres is possible. Along with transmission of information in telephone systems and similar applications, it has been suggested that optical devices may replace conventional electronics in more advanced applications such as computers. For such applications, it will be necessary to develop optical switches, amplifiers, and so on. In the last two decades, new materials have been developed that may form the basis of integrated optical circuits. These materials are photonic crystals. 

Other potential applications of photonic crystals include crystals with rows of holes to guide radiation around sharp bends (something that cannot be attained with conventional optical fibres), nanoscopic lasers formed from thin films, ultrawhite pigment formed from a regular array of submicron titanium dioxide particles, radio frequency reflectors for magnetic resonance imaging (MRI) and LEDs. 

Our experimental setup of the 2D-CARS microscope is shown in Fig. 5.4h [32], The 70-fs output from the Ti sapphire oscillator was split into two beams. One of the beams was introduced into a photonic crystal fiber (Crystal Fibre, Femtowhite 800) to generate a coherent supercontinuum. Then, the continuum was conditioned with an 800 nm long-pass filter. The other beam was spectrally narrowed by the custom-made laser line filter (Optical Coatings Japan, Av = 14 cm FWHM). The obtained two beams were introduced collinearly into the microscope objective lens. The chirping of the broadband pump beam was carefully avoided so that the CARS signals are obtained in a wide spectral region. The broadband CARS emission in back-reflected direction was analyzed by the CCD spectrometer. 

Fini JM (2004) Microstructure fibres for optical sensing in gases and liquids. Meas Sd Technol 15 1120-1128 Frazao O, Santos JL, Araujo EM, Ferreira LA (2008) Optical sensing with photonic crystal fibers. Laser Photon Rev 2(6) 449- 59... 

Wehrspohn, R.B., et al. Photonic crystal gas sensors. 17th Int. Conf on Optical Fibre Sensors (OFS-17), Bruges, Belgium, SPIE-Vol. 5855 (2005), pp. 24-29... 

Bjarklev, A., et al. Photonic crystal structures in sensing technology. 2nd Europ. Workshop on Optical Fibre Sensors, Santander, Spain, SPIE-Vol. 5502 (2004), pp. 9-16... 

The use of multi-layer systems as a preform for microdrawing allows for the production of glass elements with new optical properties [122,123] which may find apphcations in optical filters and interference devices. The most common apphcation of drawn elements, however, is in fibre optics and photonic crystals [52,292,432]. 

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