We have determined the potassium penetration cross-section in chemically tempered glasses by nondestructive nonlinear refraction measurements. The nonlinear refraction as a function of the depth was measure by the Nonlinear Ellipse Rotation (NER) signal using ultrafast laser pulses (40 fs, 1 kHz, ~2000 GW/cm2 at 780 nm) from an amplified laser system. For local NER measurements, we have used a long distance objective (20x, 1.5 cm WD) which provides a relatively good penetration resolution (~5.5 microns). We characterized several glasses with different ion exchange treatment time. The potassium penetration depth and cross-section could be correlated with the materials’ hardness.
Continuously tunable sources with room-temperature operation are required in the mid-infrared region for applications
such as spectroscopy or pollutants monitoring. In this spectral range, optical parametric oscillators (OPOs) are more
versatile than laser diodes.
Guided-wave OPOs constitute a promising perspective, thanks to higher conversion efficiency provided by the
confinement of the interacting waves. While LiNbO3 has been the crystal of choice for a long time, GaAs is a good
alternative thanks to higher nonlinearity, broader transparency range, and optoelectronic integrability. So far, a GaAs
integrated OPO has not yet been demonstrated due to technology induced propagation losses.
Here we present a detailed investigation of the propagation losses in partially oxidized multilayer GaAs/AlAs
waveguides. We have studied the impact of oxidation on the roughness of the multilayer interfaces, via transmission
electron microscopy. While the roughness of our MBE-grown GaAs/AlAs heterostructures is the standard 0.3 nm, it
increases to at least 0.53 nm after AlAs oxidation. Semi-analytical modeling shows that this level of roughness is
responsible for scattering losses, in fair agreement with the measured values. Optimization of the oxidation process is
currently under way with the aim of reaching the OPO oscillation threshold.
Access to the requested content is limited to institutions that have purchased or subscribe to SPIE eBooks.
You are receiving this notice because your organization may not have SPIE eBooks access.*
*Shibboleth/Open Athens users─please
sign in
to access your institution's subscriptions.
To obtain this item, you may purchase the complete book in print or electronic format on
SPIE.org.
INSTITUTIONAL Select your institution to access the SPIE Digital Library.
PERSONAL Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.