Spectral Measurement of the Film-Substrate Index Difference in Proton-Exchanged LiNbO(3) Waveguides

We report the spectral characterization of proton-exchanged lithium niobate (PE:LiNbO(3)) waveguides in terms of the variation of the refractive-index difference between the waveguiding layer and the substrate. The dispersion of the extraordinary refractive-index increase (deltan(e)) is measured from 405 to 1319 nm with several light sources. Two types of proton-exchanged waveguide, prepared under different conditions, are studied. These measurements should be of use in the optimization of PE:LiNbO(3) waveguides for nonlinear optical applications, particularly in second-harmonic generation in the blue-green wavelength region.     

Gain measurements in the KrCl excimer laser

The single-pass/double-pass amplified spontaneous emission technique has been used to measure the net gain at 222.4 nm in a discharge-pumped UV-preionized KrCl laser. The net gain has been measured as a function of pump rate and total pressure in He- and Ne-based gas mixtures. A maximum net gain of 0.15 cm(-1) has been obtained in a 0.09% HC1/10.1% Kr/1.5% He/88.3% Ne mixture at a total pressure of 355 kPa and at a specific power loading of approximately 21 MW/cc. The data presented are compared with previous net gain measurements performed using the passive absorption cell method.