N. Nishida

Synthesis of rare gas‐halide mixtures resulting in efficient XeF(C→A) laser oscillation

Significantly improved XeF(C→A) laser performance has been achieved using electron beam excitation of complex, multicomponent gas mixtures specifically tailored so as to reduce medium transient absorption in the blue‐green region. Use of Ar and Kr together as the effective rare gas buffer‐energy transfer species, along with a combination of NF3 and F2 to produce the desired F‐donor molecule characteristics, has permitted synthesis of near optimum medium properties for which XeF(C) is produced efficiently while transient absorption is minimized. With this technique we have achieved laser pulse energy density and intrinsic efficiency of 2.2±0.3 J/l and ∼1.5%, respectively, values that are comparable to those of the B→X rare gas‐halide lasers.

Theoretical evaluation of a short-pulse electron-beam-excited XeF(B→X) laser using a low-pressure, room-temperature Ar/Xe/F2 gas mixture

A simulation code for an electron‐beam‐excited XeF(B→X) laser using Ar/Xe/F2 gas mixtures is described. The validity of the code was checked by comparing the computed results to those obtained in a previously reported experiment with a 65‐ns, 1.14‐MW/cm3 excitation pulse. Good agreement is demonstrated for sidelight fluorescence, laser waveforms, output power, and energy. Furthermore, the simulation code analysis suggests that the XeF laser can be operated effectively with low‐pressure (<1 atm) Ar/Xe/F2 mixtures at room temperature. A maximum intrinsic efficiency of ∼3% is obtained at a total pressure of 0.5 atm. Such a low‐pressure Ar/Xe/F2 laser gas mixture would permit operation of a scaled‐up XeF laser system since the intrinsic efficiency is as high as that with conventional high‐pressure (∼3 atm) Ne/Xe/NF3 mixtures.

Simultaneous UV/visible laser oscillation on the B &#8594; X and C &#8594; A XeF excimer transitions

Simultaneous laser oscillation from the 351 nm XeF( B \rightarrow X ) transition and the broad-band XeF (C \rihgtarrow A) transition centered near 475 nm has been demonstrated using intense, short-pulse electron-beam excitation of high-pressure gas mixtures. Analysis of the causes of transient absorption suggests that it may be possible to obtain efficient UV/visible laser oscillation from each of the XeF excimer transitions excited in the same medium.

Intrinsic efficiency comparison in various low‐pressure XeF laser mixtures pumped at high excitation rates and with short‐pulse electron beam pumping

A comparison of XeF(B→X) laser efficiency is reported using four different gas mixtures at room temperature, i.e., Ar/Xe/F2 , Ar/Xe/NF3 , Ne/Xe/F2 , and Ne/Xe/NF3 . All mixtures were pumped at the same high excitation rate of 1.1 MW/cm3 with a 65 ns electron beam current pulse. The respective pressure for the Ne‐based mixtures was 1170 Torr and for the Ar‐based mixtures was 711 Torr. The measured intrinsic efficiency of all four mixtures was ∼2%, which is comparable to those reported in high‐pressure mixtures pumped at low excitation rates with long electron beam pumping.

Efficient narrow spectral output in the blue‐green region from an injection‐controlled electron‐beam excited XeF (C→A) laser

Efficient, narrow spectral output has been achieved by injection control of an electron‐beam excited XeF (C→A) laser medium using a 482‐nm dye laser pulse having a spectral width of 0.01 nm. The energy density and intrinsic efficiency characteristic of the amplified output beam were 3 J/l and approximately 2.5%, respectively, and the spectral width was on the order of that of the injected pulse.

Wideband tuning of the blue-green XeF (C→A) laser

Efficient wavelength tuning from 446 to 524 nm with a minimum spectral linewidth of 1 nm was demonstrated for an electron beam pumped XeF(C→A) laser. Energy densities of 0.1 J/l were obtained for an optimized Ar/Kr/Xe/F2/NF3 mixture.

Optimization Of Broadband Electrically Excited Excimer Lasers

In this paper the factors controlling the performance of electron beam-pumped, broadband diatomic and tri-atomic rare gas-halide excimer lasers are discussed. Particular attention is directed toward the blue/green in the XeF(C>A) laser centered at 485 nm, for which significantly improved performance has been obtained by selective tailoring of mixture kinetic processes. Maximum XeF(C>A) laser output energies in excess of 1.5 J/liter have been achieved, corresponding to an intrinsic efficiency of approximately 1%.