Impedance measurements with second-order harmonic oscillator for testing food sterility

Impedance measurements with second-order harmonic oscillator for testing food sterility

In this paper, we present a simple interface circuit for measuring impedance based on a second-order harmonic oscillator. The circuit is intended for testing the sterility of aseptically packed food products, where it must measure the conductivity changes of the packaged food in a nondestructive way. The measured impedance is modeled as a low-ohmic resistor (representing the conductivity of the...

Harmonic entanglement with second-order nonlinearity.

We investigate the second-order nonlinear interaction as a means to generate entanglement between fields of differing wavelengths and show that perfect entanglement can, in principle, be produced between the fundamental and second-harmonic fields in these processes. Neither pure second-harmonic generation nor parametric oscillation optimally produce entanglement; such optimal entanglement is ra...

High Selectivity Coupled Line Impedance Transformer with Second Harmonic Suppression

This paper presents a design of an impedance transformer (IT) with high frequency selectivity characteristics. The frequency selectivity can be controlled by evenand odd-mode impedance of a shunt coupled transmission line (TL). For experimental validation, a 50to 20Ω IT was implemented at a center frequency (f0) of 2.6 GHz for the long-term evolution signal. The measured results were in good ag...

Harmonic Analysis Techniques for Second Order

Impedance matching in photonic crystal microcavities for second-harmonic generation.

By numerically integrating the three-dimensional Maxwell equations in the time domain with reference to a dispersive quadratically nonlinear material, we study second-harmonic generation in planar photonic crystal microresonators. The proposed scheme allows efficient coupling of the pump radiation to the defect resonant mode. The outcoupled generated second harmonic is maximized by impedance ma...