[en] This proceedings contains articles of the 9th International Symposium on Laser Spectroscopy. It was held on 2-3 Nov 2001 in Taejeon, Korea. The main topics are as follows: Laser Isotope, Laser Spectroscopy, Laser Fusion, Laser Applications and so on. (Yi, J. H.)

[en] Diode-pumped solid-state microchip lasers are compact, reliable, and efficient sources of coherent radiation. They can provide excellent spatial mode quality and narrow linewidths. Numerous materials have been investigated to developed more efficient and higher power microchip lasers. Recently, high-optical-quality transparent Nd:YAG ceramics with up 9 at.%Nd³⁺ have been produced by the technique described in Ref. 2. The flexibility of ceramic materials opens new pathways for advanced microchip solid-state laser. Topics include the spectroscopic properties, laser performances, and thermal birefringence effects in highly Nd-doped YAG ceramics.

[en] Spatial distortions, such as self-focusing, self-defocusing and conical emission, of the pulsed laser beam interacting with near-resonant samarium atoms are modified using electromagnetically induced transparency. Depending on the power and the detuning of the coupling and the probe lasers, beam shape is retrieved.

[en] We report experimental demonstration of quantum jump of intracavity photon number in the many-atom microlaser. The jump occurs when the averaged intracavity atom number is larger than a critical value, about 300 in our experiment. A hysteresis-like feature was observed in the intracavity photon number as a function of cavity-atom detuning.

[en] Ring opening dynamics of diarylethene derivative (BTF6) in n-hexane are studied by femtosecond transient absorption and time resolved spontaneous fluorescence techniques. Cyclo-reversion time constant is obtained.

[en] MC(Monte-Carlo)-PIC(Particle-in-cell) simulation were carried out for the charge exchange process between Sm and Sm⁺ in laser produced plasma. The electrostatic field ws treated using the PIC method. For the calculation of the electric field, quadratic interpolation of macro-particle is adapted. For the various background neutral atom density plasma decay phenomena were investigated.

[en] We developed a tunable single mode diode laser. The laser has center wavelength of 780 nm. An 1800 line/mm grating was used for dispersion and retroreflection. Cavity length of the laser was reduced to 28 mm. A thermoelectric cooler was used for temperature stabilization. Although the laser showed nearly circular beam profile at far field region, it was partially elliptic at near the laser. To transform the beam shape to circular distribution, we send the laser beam through a single mode optical fiber.

[en] World largest Patawatt Laser is constructed to investigate the fast ignitor concept of laser fusion. It can deliver 1 PW output with 500 J in 0.5 ps. The laser system consist of (1) the front end, including a Nd:glass oscillator, two pulse stretchers and two pre-amplifiers, (2) the 350 mm aperture Cassegrain disc amplifier, (3) the beam transport optics, including a spatial filter, a Faraday rotator, a deformable mirror and a beam expander to 500 mm, (4) the pulse compressor and (5) the beam focusing optics.

[en] The higher order Q-parameter, Q ^(N) is introduced to generalize the higher order sub-Poissonian photon statistics of light. An example is provided, which has the higher order sub-Poissonian photon statistics but not the ordinary sub-Poissonian photon statistics.

[en] Structures and energies of van der Waals complexes consisting of fluorene have been studied by means of two-photon ionization spectroscopy. Time of flight photoionization mass spectrum measured in a supersonic molecular beam revealed the formation of up to octomer of fluorene. Plausible structures and energies of various fluorene dimers and trimers were predicted at the B3LYP DFT/4-31G level.