摘要:
An optical device is provided comprising a delay region having a photonic band structure, an optical input, an optical output, wherein the optical input is adapted to couple input optical signals into a predetermined mode in the delay region such that the optical signal is slowed and wherein the optical output includes a wavelength selective element. Input optical signals are coupled into a highly dispersive mode in the delay region in which the group velocity of the optical signal is reduced. The input signal, which has been delayed and dispersed, is recovered at the output of the device using the wavelength selective element.
摘要:
An optical system includes a delay region having a photonic band structure, a modulated optical signal source, an optical input, and an optical output. The optical input couples modulated input optical signals into a predetermined mode in the delay region such that group velocity of the optical signal is reduced. The optical output includes a wavelength selective element. Input optical signals are coupled into a highly dispersive mode in the delay region in which the group velocity of the optical signal is reduced. The input signal, which has been delayed and dispersed, is recovered at the output of the device using the wavelength selective element.
摘要:
The disclosure relates to a material having a textured surface and exhibiting absorption of electromagnetic waves with gigahertz frequencies. The textured surface can comprise a plurality of protrusions that can permit absorption of such waves. Morphology of the plurality of protrusions can control the absorption properties, e.g., absorption coefficients or specific frequency of absorbed electromagnetic radiation, of such materials. The material can comprise an electrically conductive thermoplastic composite. At least some of the protrusions can be formed of such composite. The material having the texture surface can exhibit broadband absorption.
摘要:
In order to create an optical device with a photonic band gap extending in two dimensions and with very uniform properties in any direction and for any polarisation state, to within 1%, air holes are etched within a substrate of low refractive index material such silicon oxynitride or silica glass. The ratio of air hole area to the remainder of the substrate is low, being less than 35%. The air holes define a quasicrystal structure, having twelve fold symmetry, being based on a square-triangle system. In another development, an etched substrate with a regular crystal structure or quasicrystal structure exhibits a non-linear refractive index. Two adjacent areas in such a substrate have different lattice properties, or have defects in the lattices, to create a unidirectional transmission path (diode action). A further beam of light may be used to modulate the transmission path by reason of the non-linear refractive index.
摘要:
A portable workstation is provided that includes a lower work surface and an upper work surface, where the upper work surface is supported by at least one support member that maintains the upper work surface and the lower work surface in a tiered, spaced apart relationship with one another. The portable workstation includes at least one pair of fastening members positioned on the underside of the lower work surface for securing the workstation across horizontal stabilizing bars of an exercise machine. The mounting members may be adjustable straps, such as Velcro® strap, for removeably coupling the workstation to the exercise machine.