Cotton in the new millennium: advances, economics, perceptions and problems

Cotton is the most significant natural fibre and has been a preferred choice of the textile industry and consumers since the industrial revolution began. The share of man-made fibres, both regenerated and synthetic fibres, has grown considerably in recent times but cotton production has also been on the rise and accounts for about half of the fibres used for apparel and textile goods. To cotton’s advantage, the premium attached to the presence of cotton fibre and the general positive consumer perception is well established, however, compared to commodity man-made fibres and high performance fibres, cotton has limitations in terms of its mechanical properties but can help to overcome moisture management issues that arise with performance apparel during active wear. This issue of Textile Progress aims to: i. Report on advances in cotton cultivation and processing as well as improvements to conventional cotton cultivation and ginning. The processing of cotton in the textile industry from fibre to finished fabric, cotton and its blends, and their applications in technical textiles are also covered. ii. Explore the economic impact of cotton in different parts of the world including an overview of global cotton trade. iii. Examine the environmental perception of cotton fibre and efforts in organic and genetically-modified (GM) cotton production. The topic of naturally-coloured cotton, post-consumer waste is covered and the environmental impacts of cotton cultivation and processing are discussed. Hazardous effects of cultivation, such as the extensive use of pesticides, insecticides and irrigation with fresh water, and consequences of the use of GM cotton and cotton fibres in general on the climate are summarised and the effects of cotton processing on workers are addressed. The potential hazards during cotton cultivation, processing and use are also included. iv. Examine how the properties of cotton textiles can be enhanced, for example, by improving wrinkle recovery and reducing the flammability of cotton fibre

Novel holographic masking technique for Bragg reflector inscription on integrated optics components

A novel triangular interferometer configuration is used to inscribe periodic or aperiodic patterns with micronic or submicronic fringe spacing. It is employed to realize Bragg reflectors or resonant grating filters on integrated optical components

Bragg mirror inscription on LiNbO3 waveguides by index microstructuration

Numerous applications in integrated optics, especially those related to multiwavelength telecommunications, require dichroic reflectors for use as narrowband or broadband wavelength-selective filters. Bragg mirrors are excellent candidates for this purpose, and we describe a method of fabricating Bragg grating reflectors in Ti-indiffused Lithium Niobate single-mode waveguides based on holographic masking in association with proton exchange. The holographic setup is employed to record a photolithographic mask directly on the substrate, enabling the inscription of waveguides with both periodic and aperiodic distributed parameters