Step-index profile

About: Step-index profile is a research topic. Over the lifetime, 3104 publications have been published within this topic receiving 53199 citations.

Photonic crystal structure and surface-emitting laser using the same

Abstract: A structure includes a photonic crystal layer which has a first member having a first refractive index and having a surface with a plurality of holes periodically arranged therein, and includes a low-refractive-index layer adjacent to the photonic crystal layer and having a second refractive index that is lower than the first refractive index. The relative refractive index difference between the first refractive index and the second refractive index is 0.10 or lower. Third members having a third refractive index that is higher than 1.0 are disposed in the holes.

Dispersion and dispersion slope compensating fiber and optical transmission system utilizing same

Abstract: A dispersion and dispersion slope compensating optical fiber (10) includes a segmented core (12, 14, 16, 18) and a cladding layer (20) wherein the refractive index profile is selected to provide a dispersion having a maximum deviation of less than 7 ps/nm-km over a wavelength band from 1550 nm to 1610 run. According to a further embodiment of the invention, a dispersion compensating optical fiber is provided having a refractive index profile with a central core segment having a positive relative refractive index; a depressed moat segment on a periphery of the central core segment having a relative refractive index that is more negative than -1.2 %; and an annular ring segment outward from the depressed moat segment having a relative refractive index that is greater than 1.2 %.

Etching Bragg gratings in Panda fibers for the temperature-independent refractive index sensing

Abstract: We demonstrate the evolution of the Bragg gratings inscribed in Panda fibers with chemical etching. The resonance wavelengths can blueshift with cladding reduction similar to the conventional counterparts. But the wavelength separation between the two polarizations is co-determined by the stress and the asymmetric shape effects. The fast and slow axes of the fiber can be reversed with each other and zero birefringence can be achieved by chemical etching the structure. When the stress-applying parts of the fiber are removed, the finalizing grating can be exploited for the temperature-independent refractive index sensing, since the modes corresponding to the two polarizations exhibit the dissimilar responses to the external refractive index change but the same response to temperature. Our device is featured with easy achievement, spectral controllability, and relative robustness.

Lens Having Circular Refractive Power Profile

Abstract: A lens having a circular refractive power profile is characterized in that, in at least one semi-meridian located between semi-meridians having the minimum and the maximum refractive power of the lens, it has a discrete refractive power which is between the minimum and the maximum refractive power of the lens

Antireflection coating, optical element, and optical transceiver module

Abstract: An antireflection coating provided on an optical element which passes through at least two wavelengths of light in the wavelength range of 1300-1600 nm, wherein the antireflection coating comprises: a high refractive index layer; a low refractive index layer having a refractive index lower than a refractive index of the high refractive index layer; and a supplementary layer having a composition different from a composition of the high refractive index layer or from a composition of the low refractive index layer, and being provided adjacent to the high refractive index layer or to the low refractive index layer.