Orientation-dependent bending properties of selectively-filled photonic crystal fibres

A selective-filling technique was demonstrated to improve the optical properties of photonic crystal fibres (PCFs). Such a technique can be used to fill one or more fluid samples selectively into desired air holes. The technique is based on drilling a hole or carving a groove on the surface of a PCF to expose selected air holes to atmosphere by the use of a micromachining system comprising of a femtosecond infrared laser and a microscope. The exposed section was immersed into a fluid and the air holes are then filled through the well-known capillarity action [1, 2]. Provided two or more grooves are fabricated on different locations and different orientation along the fibre surface, different fluids may be filled into different air-holes to form a hybrid fibre. As an example, we filled half of a pure-silica PCF by a fluid with n=1.480 by carving a rectangular groove on the fibre (Figure 1). Consequently, the half-filled PCF became a bandgap-guiding structure (upper half), resulted from a higher refractive index in the fluid rods than in the fibre core [3], and three bandgaps were observed within the wavelength range from 600 to 1700 nm. Whereas, the lower half (unfilled holes) of the fibre remains an air/silica index-guiding structure (Figure 1(b)). When the hybrid PCF is bent, its bandgaps gradually narrowed, resulted from the shifts of the bandgap edges. The bandgap edges had distinct bend-sensitivities when the hybrid PCF was bent toward different directions. Especially, the bandgaps are hardly affected when the half-filled PCF was bent toward the fluid-filled region. Such unique bend properties could be used to monitor simultaneously the bend directions and the curvature of the engineering structures

Selectively fluid-filled microstructured optical fibers and applications

A versatile technique based on micromachining is demonstrated to fill selectively one or several different types of fluids into desired air holes in a microstructured optical fiber (MOF). Unique optical properties and applications of the selective-filled MOF are investigated

Does Telehealth Reduce Rural-Urban Care Access Disparities? Evidence from Covid-19 Telehealth Expansion

Using hospital claims data, we study the effect of telehealth expansion on the disparities between care access in rural and urban areas during Covid-19. We use urban areas as the control group and compare the changes in patients' access to care before and after the telehealth expansion. We find that the rural-urban disparities in overall access to care (i.e., the total number of visits) remain unchanged after the policy. We further distinguish in-person from telehealth visits and find enlarged disparities in patients' visiting modalities. In particular, urban patients substitute in-person visits with telehealth visits, yet rural patients have a much lower adoption rate of telehealth services and continue with in-person visits. Finally, we perform visit-level analyses and identify patients' social determinants and physicians' characteristics associated with telehealth adoptions

The Development of Jingdezhen in the View of Cultural Innovation

Jingdezhen porcelain is famous all over the world. During the development of ceramics, with continuous cultural innovation and technological progress, it created the legends of the city development. But in modern times, the development of Jingdezhen was in trouble. How to reshape the glorious city and realize the sustainable development of the economy? This paper, from the perspective of cultural innovation, Jingdezhen in space, time, technology, brand many dimensions, Jingde town development and urban construction are put forward for sustainable development train of thought.Key words: Cultural innovation; Jingdezhen; Ceramics; Urban developmen