Robert C. Sze

Crystal growth and optical characterization of cerium-doped Lu1.8Y0.2SiO5

Czochralski growth of cerium-doped Lu1.8Y0.2SiO5 (LYSO) from a 90/10 solution of Lu2SiO5 (LSO) and Y2SiO5 (YSO) is demonstrated. The alloyed scintillator retains the favorable growth properties of YSO and the desirable physical and optical scintillator properties of LSO. Radioluminescence, thermally stimulated luminescence, optical absorption, and lifetime measurements confirm the equivalence of LYSO and LSO optical properties. Advantages of LYSO Czochralski growth relative to LSO include reduced melting point, less propensity for formation of crystalline inclusions, lower cost of starting material, and easier incorporation of cerium into the host lattice. This material offers an attractive alternative to LSO for scintillator applications.

New lines in the UV: SRS of excimer laser wavelengths

The UV excimer lasers ArF, KrCl, KrF, and XeCl were utilized to create new families of UV lines by multiple orders of broad-band nonresonant stimulated Raman scattering (SRS) in the media H 2 , D 2 , CH 4 , and LN 2 . Mixed-media and excited-state SRS were also studied.

Efficient Raman shifting of ArF and KrF laser wavelengths

A series of uv lines has been generated in the region 190–360 nm by multiple Raman scatterings of the ArF and KrF laser wavelengths. ArF has been shifted in H2 and KrF shifted in H2, D2, and CH4. For the optimized case of KrF pumping H2, better than 50% energy conversion was observed to the first Stokes at 2769 A.

Experimental studies of a KrF and ArF discharge laser

We have explored the operating characteristics of UV preionized discharge lasers producing 10-100 mJ from noble-gas/ monofluoride excimers. We have studied in detail the temporal characteristics of the discharge, the effects of instabilities, variations of circuit parameters, and the effects of varying degrees of preionization on energy deposition and lasing. Spectral characteristics, tuning, stable and unstable resonator geometries, and beam focusability are also discussed. A companion paper presents the results of a computer modeling of the laser.

Rare-gas halide avalanche discharge lasers

This paper summarizes a series of studies aimed at understanding rare-gas halide lasers excited by UV preionized avalanche discharges. Discussions include steady-state rate equation calculations of the kinetics, parametric variations and optimizations of discharge characteristics, and gas mixture optimizations for high-energy lasing.

Infrared second‐harmonic generation in nonbirefringent cadmium telluride

We have experimentally demonstrated infrared second‐harmonic generation in the nonbirefringent zinc‐blende crystal cadmium telluride using properly oriented plates in which the optical path length is equal to an odd number of coherence lengths. The present process has the promise of scalability to high power, since suitable zinc‐blende cubic crystals can be grown in large boules of excellent optical quality.

Operating characteristics of a high repetition rate miniature rare-gas halide laser

Performance characteristics of a high repetition rate rare-gas halide minilaser are reported. At 1 kHz pulse repetition frequency over 1 mJ per pulse at KrF and 0.5 mJ per pulse at XeCl wavelengths are obtained. Net small-signal gains greater than 0.3 cm-1are observed in XeCl. The wall plug efficiency is measured to be as high as 0.25 percent.

120‐ps duration pulses by active mode locking of an XeCl laser

A short actively mode‐locked XeCl oscillator has produced 120‐ps duration pulses for the first time. The pulses have an energy of 15 μJ and a modulation depth of >95%. The evolution of the pulsewidth during the mode‐locked pulse train was also measured.

Inductively stabilized rare‐gas halide minilaser for long‐pulsed operation

Inductively stabilized discharges are developed for the rare‐gas halide minilasers. 6.8 mJ per pulse with 40‐ns full width at half‐maximum pulse lengths and 3.7 mJ per pulse with 60‐ns full width at half‐maximum pulse lengths are obtained for KrF. 3.1 mJ per pulse with 40‐ns full width at half‐maximum pulse lengths and 1.7 mJ per pulse with 60‐ns full width at half‐maximum pulse lengths are obtained in XeCl. The discharge dimensions are 2.5‐mm electrode separation by 4 mm wide and 27.6 cm long. Orders of magnitude increases in pulse repetition frequency are obtained in devices that do not utilize gas flow.

Intense lasing in discharge excited noble‐gas monochlorides

Intense lasing of XeCl (180 mJ) and KrCl (100 mJ) occurs using HCl as the halogen doner. The low energies obtained from e‐beam devices are believed to result from Ar+2 molecular‐ion absorption. Very long XeCl lasing lifetime with respect to gas fill is observed; this is postulated to be the result of photodissociation of Cl2 due to the laser wavelength which, in turn, results in enhanced rates for the formation of HCl.