We carry out wavelength-dependent second harmonic interference experiments using thin films of an organic dye as nonlinear optical sources. While the measured difference of refractive index between the fundamental and second harmonic wavelengths follows the theoretical expectation for air in a wide spectral region, anomalous dispersion is observed when the second harmonic light lies in the abso...

The dispersion relation is fundamental to a physical phenomenon that develops in both space and time. This equation connects the spatial and temporal frequencies involved in the dynamic process through the material constants. Electromagnetic plane waves propagating in homogeneous media are bound by simple dispersion relation, which sets the magnitude of the spatial frequency, k, as being propor...

We have studied wideband dispersion-free slow light in photonic crystal waveguides and other photonic nanostructures, which allows tunable delays in short optical pulses and the enhancement of light-matter interaction. This paper demonstrates the state-of-the-art devices fabricated by CMOS-compatible process, where compact devices of 200 – 400μm lengths are integrated with Si photonics componen...

We present an analytic theory of timing jitter in dispersion-managed light-wave systems that is based on the moment method and the assumption of a chirped Gaussian pulse. We apply the theory to a soliton system and show that 50% postcompensation of the accumulated dispersion can reduce the jitter by a factor of 2. We also apply the theory to a low-power light-wave system employing the return-to...

We investigate dispersion properties of photonic crystal waveguides in a low-index material system. The modes above the light line, of a waveguide consisting of one row of missing holes (W1), exhibit high losses due to out-ofplane radiation. In contrast, the index-guided modes below the light line show moderate losses and we demonstrate both theoretically and experimentally that high dispersion...

The photocatalytic effect of TiO2 has great potential for the disinfection of surfaces. Most studies reported in the literature use UV activation of TiO₂, while visible light has been used only in a few applications. In these studies, high concentrations of TiO₂, which can compromise surface properties, have been used. In this work, we have developed an acrylic-water paint dispersion containing...

The velocity of light in vacuum, c, is approximately 3 × 108 m s–1, fast enough to make 7.5 round-the-world trips in a single second, and to move a distance of 300 mm in 1 ns. This ultrahigh speed is advantageous for efficient data transmission between two points, whether they are separated on a global scale or on a single chip; however, it also makes control of optical signals in the time doma...

A chip-based temporal compressor for shortening the duration of optical pulses has been developed by scientists in Japan. The scientists at Yokohama National University made their compressor from a silicon photonic crystal waveguide. Co-propagating slow light is used as a control pulse and serves to induce carrier plasma dispersion in the waveguide through two-photon absorption. The efficiency ...

A compact and practical white-light cross-correlator suitable for fast evaluation of femtosecond optics, in terms of group-delay dispersion, was developed. A 40-W tungsten-halogen lamp was used as a white-light source and the detector selection was made so as to have adequate spectral sensitivity from 600 to 1050 nm, peaked at 800 nm. Group-delay dispersion was obtained, with femtosecond time r...

Strongly anisotropic media where the principal components of electric permittivity or magnetic permeability tensors have opposite signs are termed as hyperbolic media. Such media support propagating electromagnetic waves with extremely large wave vectors exhibiting unique optical properties. However, in all artificial and natural optical materials studied to date, the hyperbolic dispersion orig...