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In this paper, we report the mode area scaling of a rare-earth doped step index fiber by using low numerical aperture. Numerical simulations show the possibility of achieving an effective area of ~700um 2 (including bend induced effective area reduction) at a bend diameter of 32cm from a 35μm core fiber with a numerical aperture of 0.038. An effective single mode operation is ensured following the criterion of the fundamental mode loss to be lower than 0.1dB/m while ensuring the higher order modes loss to be higher than 10dB/m at a wavelength of 1060nm. Our optimized modified chemical vapor deposition process in conjunction with solution doping process allows fabrication of an Yb-doped step index fiber having an ultra-low numerical aperture of ~0.038. Experimental results confirm a Gaussian output beam from a 35μm core fiber validating our simulation results. Fiber shows an excellent laser efficiency of ~81% and a M 2 less than 1.1. 2015 Optical Society of America OCIS codes: (060.2280) Fiber design and manufacturing; (140.3510) Fiber lasers.

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This article presents the results ofa study ofconcern about crime and fear ofcrime in an Australian rural community. Previous urban research on this topic, which has established socio-demographic correlates offear and concern, is reviewed. The limited number of rural studies is discussed and reasons for the significance of "community" in the context offear and concern in rural research are considered. The results of the study in terms of socio-demographic correlates are consistent with those of previous urban research. Community variables such as community satisfaction, community trust, associational membership, and number ofrelatives in the area are also significantly linked with concern about crime andfear ofcrime. The implications ofthe study's results are discussed.

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