This PDF file contains the front matter associated with SPIE Proceedings Volume 6611, including the Title Page, Copyright information, Table of Contents, Introduction (if any), and the Conference Committee listing.

The alternative method of atomic iodine generation by chemical process from gaseous reactants for a chemical oxygen iodine laser (COIL) was experimentally investigated. Research on efficiency of the atomic iodine generation, suitable configuration of iodine atom injection into the laser cavity and small signal gain measurements was performed, and some results were included in this contribution.

Results of theoretical and experimental research of the edge reflection effects in the technologic CW C0₂-laser with flowing active medium are discussed. It is shown, that diminishing reflections at edges of the out coupling mirror essentially improves the quality of the output beam.

Admixing of iodide to the effluent of MW discharge in oxygen was used to measure yield of singlet oxygen generated. Singlet oxygen yield was evaluated using the equilibrium condition. The method was absolutely calibrated using a traditional chemical singlet oxygen generator.

The paper presents the results of experimental study of the singlet oxygen (¹&Dgr;0₂) lifetime in the solution, saturated by fullerene and oxygen in CCl₄ and irradiated by optical pump with various level of power and with various spectral content. It was shown that in the case of absence of the UV component in this optical pump, i.e. in the case using of only visible spectral range, the lifetime of ¹&Dgr;0₂ reaches ~ 50 ms for optical pump energy density of ~ 0/5 J/cm². Pulse duration was ~ 0.5- 1 ms. Such criterion makes it possible to develop the outlook of the realistic singlet oxygen generator with optical pumping of fullerenes for pulse-repetitive and CW regimes of FOIL operation.

High brightness performance of chemical oxygen iodine lasers (COIL) requires resonator concepts that enable efficient power extraction from low gain medium while the beam quality is close to the diffraction limit. The resonator shall provide straightforward alignment procedures and stable output performance for efficient laser operation. Such resonator configurations are theoretically designed and implemented in a 10 kW-class COIL. Different resonator concepts are pre-evaluated by numerical methods with regard to their design and alignment sensitivities. Promising candidates are tested for their alignment performance and brightness parameters. Among others, hybrid resonators are found to be of straightforward optical architecture meeting the above challenges. Theoretical predictions and experimental results are in excellent agreement. Therefore, further promising design approaches, like multi-pass hybrid resonators or the modified negative-branch unstable resonator, will be depicted and discussed within this paper.

The questions of optical beam quality of COIL are considered. The classification and meanings of different type of optical aberrations in COIL is presented. The ways of compensation of amplitude aberration by structure-parametrical optimization of the unstable resonator are offered. The scheme of automatically resonator alignment for compensation of phase aberrations originated from misalignment is presented. The 3D numerical modeling and investigation of gas flow and chemical kinetic in COIL is fulfilled. The scales and magnitude phase aberrations coimected with gas flow non-homogeneities are analyzed. The optimization of the COIL nozzle bank length from point of view of maximal beam brightness is fulfilled.

The efficient power operation in a chemical oxygen-iodine laser for subsonic modes has been demonstrated. It is shown that the substitution of the buffer gas N₂ by CO₂ does not cause any significant variation in the dependence of the output power on the degree ofdilution ofthe active medium. The maximum power was 581 W for the flow rate of molecular chlorine 22 mmole/s that corresponds to a chemical efficiency of &eegr;_chem = 29%.

The kinetic model of I₂ molecules dissociation in chemical oxygen iodine laser (COIL) medium taking into account interaction of the vibrationally excited iodine and singlet oxygen molecules is developed. The results of computer calculations utilizing this model are good agreement to experimental dissociation rate of iodine molecules in the media characteristic of COIL.

An ejector nozzle bank powered by centrifugal bubbling SOG is considered like highly efficient gain generating system for COIL. A high potential recovered pressure ~100 torr of the gain medium flow with a small signal gain higher than 1% cm^-1 and low oxygen plenum pressure has been demonstrated. A centrifugal bubbling SOG is an efficient source of oxygen at high pressure with high depletion of the BHP in the single burn dawn. A high 0₂(¹&Dgr;) yield and chlorine utilization higher than 90% have been obtained at chlorine gas loading up to 6 mmole/s per 1 cm² of the bubbler surface. The ejector COIL powered by centrifugal bubbling SOG demonstrated ~25% of chemical efficiency with specific power 6 kJ per 1 litre of the BHP in the single burn dawn. The combination of centrifugal bubble SOG with ejector nozzle bank can be considered as a promising gain medium flow generation system for COIL.

Extreme ultraviolet (EUV) radiation is seen as the most promising candidate for the next generation of lithography and semiconductor chip manufacturing for the 32 nm node and below. The paper describes experimental results obtained with discharge produced plasma (DPP) sources based on pinch effect in a Xe and Sn vapour as potential tool for the EUV lithography. Problems of DPP source development are discussed.

Results of research activity on development of basic technology for experimental nanolithographer with planned 10÷30 nm resolution are presented. The development circuits of illumination subsystem on base of laser produced plasma source and multimirror extreme ultraviolet reduced camera are analyzed. The manufacture technology of aspherical EUV mirrors with atomic-smooth surfaces and high-precision figure is considered. The illustrations of high-quality aspheric mirrors with supersmooth surfaces and an atomic level roughness are represented. The figure quality of 300-mm concave mirror and convex 120-mm mirrors of reduced camera measured by interferometry at &lgr; = 632 nm have been produced 0,008&lgr; rms and 0,005&lgr; rms respectively.

Advanced techniques and scheme for testing mirror shape with an accuracy of 0.001&lgr; RMS in visible light by using the point diffraction interferometer and computer processing of interferogramms are presented. The shape of aspheric EUV mirror with 300 mm diameter is characterized.

Results of experimental and theoretical investigations of discharge XeCl laser with 35 ns (FWHM) radiation pulse duration are presented. Laser generates the laser pulse energy of O.6 J with 2% total electric efficiency and 100 Hz pulse repetition rate. Calculated laser radiation parameters and discharge parameters have a good agreement with experimental results. Influence of basic plasma-chemical processes in discharge on laser output and efficiency is shown. Maximal laser efficiency relatively pumping power was 3.5%.

The high repetition rate UV lasers (XeF [1], KrF [2] and N₂) with a new electrode unit are investigated. A multisectional discharge gap 25 cm length and 1.2 cm height is formed by 25 pairs of anode-cathode plates. The discharge width is ≈ 1 mm. The average specific pump power is ≈ 9 MW cm^-3. The main aim of the work is the achievement of a maximum pulse repetition rate (f_m) with high output energy stability. At a rather low gas flow velociity ⩽ 19 m s^-1 the frequencies f as high as 4 kHz in the excimer lasers and 4.5 kHz in a nitrogen laser are realized. The relative rms deviations of the output energy (&sgr;) for XeF and KrF lasers is in the range 1-2% for f ⩽ 3 kHz and 3-4% for f = 4 kHz. For the nitrogen laser &sgr; ⩽ 1.3% is at f ⩽ 4.5 &kgr;&Ggr;ц.The average output power 10 (12) W for the XeF (KrF) laser and 1.1 W for the nitrogen laser are reached.

A pulsed transverse inductive discharge (PTID) is used to population inversion formation on the transitions in atoms and molecules. Excitation system producing an inductive discharge in gases under a pressure within a range from 0,1 to 1,0 atm has been created. The experimental study of spectral and temporal parameters of stimulated emission for active media on the Ne (585.3 nm), He (587.5, 667.8 nm), Ar (750.4nm) atoms and XeF* (353 nm), XeCl *(308 nm) and KrF* (248 nm), molecules excited by an inductive transverse discharge was performed. Lasing on the transitions of fluorine atoms and nitrogen molecules are reported. The results of the experimental study of spectral, temporal, and energy parameters of fluorine (FI) and nitrogen inductive lasers are presented.

Small signal gain temporal behavior in pulsed CO laser amplifier operating with oxygen rich gas mixtures CO:He:O₂ and CO:N₂:O₂ was experimentally studied. The rich content of oxygen in helium mixture (CO:He:O₂=1:4:2) resulted in ~8-fold increase of the maximum gain on low vibrational transitions (10-9) and strong absorption on high ones (21-20). A high efficient pulsed CO laser operating with gas mixture in which oxygen substituted for nitrogen was launched.

Vibrational distribution function (VDF) of CO molecules was measured at "on" and "off" laser radiation in CO laser excited by longitudinal DC discharge. The kinetic equation for VDF and electron Boltzmann equation are solved selfconsistently. Comparison of the experimental and theoretical laser spectra and VDF show good agreement. Effect of spectral lines selection using intracavity NO absorber on the VDF shape was studied experimentally and theoretically.

High-power gas lasers can be the effective tool in such applications as dismantlement of obsolete nuclear reactors, laser-hardening of the surfaces of railway rails etc. The carried out experiments have shown, that radio frequency (BY) discharge is an effective source of reception of the vibrational-excited CO molecules. Laser generation was shown on small-scale experimental installation. For transition to creation high-power CO laser the clear understanding of the processes occurring in a supersonic stream a CO mixture, excited by RF discharge is necessary, the calculation model of scaling CO laser with RF discharge in supersonic stream therefore was developed. The developed model, proceeding from the given power projected CO laser, allows to calculate parameters of laser installation and to optimize them with the purpose of reception of high value of efficiency and low cost of installation as a whole. The industrial CO laser for dismantlement of obsolete nuclear reactors and hardening the surfaces of railway rails is proposed. The estimated cost of laser is some hundred thousand dollars USA and small sizes of laser head give possibility to install it on manipulator without fiber-optic delivery.

Authors propose combined DC and capacitive periodic-pulsed discharge as an alternative to self-sustained DC and RF discharges for excitation of fast-axial-flow CO₂ lasers. Experiments show that output power 1.7 kW/m with discharge efficiency more than 20% may be achieved in proposed discharge scheme. Measured discharge and active medium characteristics are presented.

Air-cooled argon laser generating periodic or externally controlled microsecond pulses with 10 W of average pulse power for biomedical applications, particularly in flow cytometry, has been developed. Study of laser characteristics as dependent of discharge parameters has been performed, its output optimised, and long-term stable operation, necessary for practical use, has been achieved.

Protective single-layer, AR double-layer, and HR multi-layer fluorine-resistant coatings with damage thresholds as high as 20 J/cm² were deposited for the intracavity optics of high-energy KrF lasers by using different deposition techniques. They were tested by the atomic-force microscopy and IR Fourier spectrometry in regard of microstructure, porosity, water content, and in prolonged etching by fluorine. The most promising were NdF₃-based AR and HR coatings produced by e-beam evaporation, while outstandingly low water content was demonstrated for MgF₂ and Al₂O₃ layers deposited by laser evaporation with a preliminary laser treatment of substrates.

Beamsplitter's coatings are used for optic's instrumentation, devices for space research, laser physics, Fourier spectroscopy and many other domains of science and techniques. Their wide application causes the stimulation of investigations in the field of synthesis of new kinds of optical coatings which must have demanded optical properties. There is the special interest to beamsplitter's coatings for different kinds of radiation's polarization. In the present paper it is considered the synthesis and the fabrication of interference coatings, especially for the simultaneous splitting of CO₂-laser's polarized radiation in the proportion: 50% of s-polarized radiation to 50% of p-polarized radiation from the initial beam, falling on a coating. We searched the task's stable decision that must satisfy to the demand in the wavelength range 9÷12 &mgr;m. It was found the decision for the coating's structure, in which the refractive index was increasing at first then it was decreasing. We produced and studied beamsplitter's multiplayer coatings on ZnSe substrates. As the result of coating's examination by the polarized CO₂-laser radiation, experimental values of transmission coefficients T_s and T_p are equal T_s=T_p=(5O±2)% and have the best concordance with theoretical ones.