We present a quantitative shadowgraphic method which can measure the density of a laser-generated plasma in air with sensitivity and resolution comparable or better than traditional interferometric techniques. Simultaneous comparison of both shadowgraphy and interferometry has been carried out allowing the experimental evaluation of the reliability of the shadowgraphic method. c © 2008 Optical ...

The absolute time-dependent nonlinear response of O2, N2, N2O, and Ar to intense nonionizing, ultrashort optical pump pulses is measured with single-shot spectral interferometry. The instantaneous and delayed rotational responses are distinguished as a function of pump-pulse duration and probe central wavelength. Our measurements are central to the modeling and understanding of nonlinear propag...

An on-axis plasma density depression channel was observed during and after the passage of a relativistically and ponderomotively self-guided laser pulse through a plasma. Optical interferometry was used to produce time-resolved plasma density distributions, revealing the formation of a plasma waveguide. These results were complemented by the guiding of a collinear trailing pulse. [S0031-9007(98...

Laser interferometry serves a fundamental role in science and technology, assisting precision metrology dimensional length measurement. During the past decade, laser frequency combs---a coherent optical-microwave ruler over broad spectral range with traceability to time-frequency standards---have contributed pivotal roles ever-growing demands measurement precision. Here we report spectrally res...