Crystal-cored fibers

Nonlinear Optical Interactions in Organic Crystal Cored Fibers... 

Figure 3. Monomode benzil crystal cored fiber viewed between cross polarizers.

Figure 6. Optical SHG in benzil crystal cored fiber by coupling u "8 to the... 

Figure 7. Diagram (ui fi) showing phase-matching scheme for guided wave SHG in a biaxial crystal cored fiber with both the fundamental and the SH as HEU modes.

Kerkoc, R, Bosshard, C., Arend, H., and Gunter, R, Growth and characterization of 4-(AAf-dimethylamino)-3-acetamidonitrobenzene single-crystal core fibers, Appl. Phys. Lett., 54, 487 89 (1989). 

Harada, A., Okazaki, Y., Kamiyama, K., and Umegaki, S., Generation of blue coherent light from a continuous-wave semiconductor laser using an organic crystal-cored fiber, Appl. Phys. Lett., 59, 1535-1537 (1991). 

Figure 1.20. (a) Axial alignment of a nematic liquid crystal cored fiber, (b) mixed radial and axial align-... 

Geren, M., and S. J. Maddea 1989. Low loss nematic liquid crystal cored fiber waveguide./4pp/. Opt. 28 5202. 

In the two previous subsections, I have presented design strategies for the SPR sensors based on photonic crystal Bragg fibers. In principle, any photonic bandgap fiber can be used in place of a Bragg fiber to develop such sensors. In this section, I present an example of a SPR sensor based on a solid-core honeycomb PCF. 

A major limitation of the sensitivity of this type of sensor is the ability to transfer optical power into the evanescent field. Recent work has incorporated new types of fibers to increase the sensitivity of measurements. Newly developed hollow core fibers, which guide light mainly in the cladding, can be used to couple more power into the sensitive materials [76]. If the hollow core fiber is used as the active sensing area between two silica core fibers, then the transitions between the fibers will force the light to travel from the core into the cladding then back into the core. Another type of fiber is the microstructure fiber or photonic crystal fiber, which incorporates air holes into... 

Khoo, I. C., M. V. Wood, B. D. Guenther, Min-Yi Shih, P. H. Chen, Zhaogen Chen, and Xumu Zhang. 1998. Liquid crystal film and nonlinear optical liquid cored fiber array for ps-cw frequency agile laser optical limiting application. Opt Express. 2 471-82. 

In another approach, two cascaded microstructure-collapses on a photonic crystal fiber are intentionally introduced by C02 laser or electric arc heating31. In this way, the mismatch of core size along the fiber causes light coupling between the core and cladding modes. 

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