The present invention generally relates to the field of fiber optics, and more specifically to optical fibers, methods of manufacturing optical fibers, and methods of classifying optical fibers. In an embodiment, the present invention is a multimode optical fiber which comprises a core and clad material system where the refractive indices of the core and cladding are selected to minimize chromatic dispersion in the 850 nm wavelength window and the refractive index profile is optimized for minimum modal-chromatic dispersion in channels utilizing VCSEL transceivers. Multimode optical fibers according to this embodiment may have increased channel bandwidth.

A polarization-maintaining dispersion-compensation microstructure fiber includes an inner core, an air-hole array in area 1 and an air-hole array in area 2. The air holes in the area 1 and 2 air-hole arrays are arranged in square lattice. The air-hole arrays in areas 1 and 2 are dislocated by half-layer along y-direction. In area 1, 2 air holes in the middle row are omitted to form a solid area as the inner core. 2 outer cores are located in 2 sub-areas of area 2, and each outer core contains 2 air holes. The long (or short) axes of the inner and outer cores are perpendicular, and the center points of the inner core and the two outer cores are located on the x-axis.

Example embodiments relate to delay-line quantum memories. One example embodiment includes a device. The device includes a plurality of cascaded optical stages coupled with one another. Each optical stage includes an optical delay line. The optical delay line is configured to receive light at an input. The optical delay line is also configured to propagate light from the input to an output. Light propagates from the input to the output with an associated optical delay time. The optical delay times associated with different optical stages are different from one another. Each optical stage also includes a stage-level recirculation switch configured to receive light at the output of the optical delay line and selectively recirculate the light through the input of the optical delay line. The device also includes a device-level recirculation switch configured to receive light exiting the last optical stage and selectively recirculate the light through the first optical stage.