ObjectivesThis study aims to investigate the role of different factors associated with exposure to second-hand smoke (SHS) in the workplace and home in the urban and rural areas of India.DesignSecondary analysis of the data from the Global Adult Tobacco Survey conducted in 2009–2010.Setting and participantsData were analysed from 32 738 rural and 23 202 urban non-smokers at home and 4809 rural and 6227 urban non-smokers in the workplace in India.Outcomes and methodsWe used two measures of SHS: exposure to SHS at home and exposure to SHS in the workplace. SHS exposure at home is estimated for non-smokers who reported anyone smoking inside his/her home. Exposure to SHS in the workplace is estimated for non-smokers who reported anyone smoking in the workplace in the past 30 days before the survey. Statistical techniques such as χ2 test, logistic regression and discriminant function analysis were used.ResultsThe results showed that SHS exposure in the workplace and home is higher in the rural areas than in the urban areas. As compared with men, women are significantly more likely to be exposed to SHS at home (OR=1.20, 95% CI 1.10 to 1.30) in the rural areas, and less likely at the workplace in the urban areas (OR=0.49, 95% CI 0.40 to 0.59). Education and region are significant predictors of exposure levels to SHS at home and the workplace in the rural and urban areas. The knowledge of number of smoking-related hazards significantly discriminates the SHS exposure in the rural workplace. SHS exposure at home is most affected by region in the rural areas and education in the urban areas.ConclusionsThe factors which affect SHS exposure differ in the rural and urban areas of India. The study concludes that the risk of getting exposed to SHS at home and the workplace among non-smokers is higher in the rural areas of the country.

The paper presents selective fiber Bragg grating (FBG) inscription in four-core fiber based on a phase mask scanning method. The inscription factors are systematically investigated, which involves fiber core position and focused laser beam size in fiber, etc. Several specific inscriptions (including individual, dual and all inscriptions) are demonstrated. Two orthogonally positioned cores are selectively inscribed and applied to two-dimension vector bending measurement. The measured bending sensitivities of two FBGs range from −54.3 pm/m −1 to 52.2 pm/m −1 and −53.7 pm/m −1 to 52.8 pm/m −1 , respectively. More importantly, it has been revealed that their sensitivities versus bending direction follow regular cosinoidal and sinusoidal distribution. The direction and amplitude of the vector bending can be recovered using measured central wavelength shifts of those two FBGs.

We demonstrate acousto-optic modulation of a fiber Bragg grating in a birefringent suspended core fiber up to frequencies of 5.2 MHz for the first time. At acoustic resonances lower than 820 kHz, the reflectivity of the orthogonal polarization modes is electrically switched to a superposed reflection band with a maximum modulation depth of 51% at 10 V. The wavelength peak of the polarization modes is dynamically shifted by tuning the driven electrical signal from 1.92 to 5.2 MHz. A novel side-coupled based acousto-optic device is demonstrated, indicating new possibilities for ultracompact, fast and efficient all-fiber integrated devices.

We demonstrated a highly-efficient 2D bending sensor with great direction recognition based on the integration of a titled fiber Bragg grating (TFBG) and a specially-designed orthogonal TFBG pair. The low-order cladding modes of the sensor present significant responses to fiber bending magnitude and direction, which is the key to bending direction recognition. Meanwhile, the stable fundamental core mode can be used to monitor the system power and eliminate the temperature effect.

In this paper, we report a highly effective relative humidity (RH) sensor implemented on graphene oxide (GO) coated long period grating (LPG). The GO nanocolloides bonded onto a cylindrical fibre cladding enables the LPG with strong evanescent waves to absorb more water molecules increasing its RH sensitivity. In an LPG, the phase matching condition occurs when a forward propagating core mode is coupled with the co-propagating lower order cladding modes generating evanescent waves to interact with the surrounding medium. This unique effect of LPGs can be more enhanced with multilayer GO deposition. There is an expansion of GO film with the absorption of more water molecules as RH increases. The absorption of water molecules on GO coating increases the conducting carrier (holes) density on it, thus decreasing the refractive index of GO film. The combined effect of increasing evanescent waves and modulated refractive index makes the GO coated LPGs as effective RH sensors. Our recently achieved results have shown the RH sensitivity of the GO coated LPG is about 0.01 dB/%RH. We have also investigated the effect on GO layer thickness, showing thicker layer increases the RH response of the LPG cladding mode resonances in lower wavelength region.