The sixth harmonic (6ω, 133 nm) of a Ti:sapphire laser is generated using cascaded four-wave mixing in filamentation propagation of the fundamental (ω) and the second harmonic (2ω) pulses through Ne gas. The method provides the 6ω pulse energy higher than 5 nJ/pulse at 1 kHz and a pulse duration shorter than 17 fs without dispersion compensation.

Direct-frequency measurements have been extended into the visible region of the electromagnetic spectrum. The visible frequencies were synthesized by generating the second harmonic of the recently measured 260-THz (20)Ne, 1.15-microm laser with a LiNbO(3) crystal. The absolute frequencies of ten hyperfine components of (127)I(2) near 520 THz are reported.

Optical limiting performances of acid blue 29 are investigated under irradiation by a 35 mW continuous wave He–Ne laser. The optical limiting behavior is investigated by using transmission measurement through samples with different concentrations. Our results show that the optical limiting efficiency is concentrations dependence. Induced self-diffraction patterns are observed at relatively high...

Constant-psi constant-delta contour maps in the reduced angle-of-incidence-film-thickness plane that are useful in ellipsometry and in design of reflection-type optical devices are discussed. As a specific example, a contour map is given for the SiO(2)-Si film-substrate system at the 6328-A He-Ne laser wavelength.

The output characteristics of a corona-preionized XeCl laser are described. Measurements in an He-based mixture up to 5 bars and in an Ne-based mixture up to 10 bars are presented. The maximum obtained output energy per unit volume is more than 9 Jll.

The development of the Scanning Laser Ophthalmoscope is reviewed from a historical perspective. Since a flying-spot scanning principle for an electro-optical ophthalmoscope was first disclosed in 1950, enabling milestones have included the introduction of the laser and inversion of the usual Gullstrand's configuration of optical pupils in 1977, and the application of the optical principle of co...

A major goal in ultrashort wavelength laser research is the development of practical laser sources that can impact applications. Of particular interest is the demonstration of compact “table-top” amplifiers capable of generating soft x-ray pulses of substantial energy. Such development motivates the demonstration of gain media generated by compact devices that can be successfully scaled in leng...

We describe an apparatus for the stabilization of laser frequencies that prevents long-term frequency drifts. A Fabry–Perot interferometer is thermostated by referencing it to a stabilized He–Ne laser ~master!, and its length is scanned over more than one free spectral range allowing the analysis of one or more lines generated by other ~slave! lasers. A digital acquisition system makes the dete...

We report a simple and repeatable method for fabricating a large-area substrate for surface-enhanced Raman scattering. The substrate was processed by three steps: (i) femtosecond (fs) laser micromachining and roughening, (ii) thin-film coating, and (iii) nanosecond laser heating and melting. Numerous gold nanoparticles of various sizes were created on the surface of the silicon substrate. The 3...

Many organisms divide chromosomes within the confines of the nuclear envelope (NE) in a process known as closed mitosis. Thus, they must ensure coordination between segregation of the genetic material and division of the NE itself. Although many years of work have led to a reasonably clear understanding of mitotic spindle function in chromosome segregation, the NE division mechanism remains obs...