Quasi-static Optical Parametric Amplification

TL;DR

This paper demonstrates a novel dispersion-engineered lithium niobate nanowaveguide that achieves extremely high optical parametric gain with very low pulse energy by creating a quasi-static amplification process.

Contribution

The work introduces a dispersion engineering approach in thin-film lithium niobate nanowaveguides to enable high-gain, low-energy optical parametric amplification without pulse distortion.

Findings

Achieved parametric gains up to 88 dB with pulse energies over 10 pJ.

Eliminated multiple dispersion orders to enable quasi-static amplification.

Demonstrated significant reduction in energy requirements compared to previous methods.

Abstract

High-gain optical parametric amplification is an important nonlinear process used both as a source of coherent infrared light and as a source of nonclassical light. In this work, we experimentally demonstrate an approach to optical parametric amplification that enables extremely large parametric gains with low energy requirements. In conventional nonlinear media driven by femtosecond pulses, multiple dispersion orders limit the effective interaction length available for parametric amplification. Here, we use the dispersion engineering available in periodically poled thin-film lithium niobate nanowaveguides to eliminate several dispersion orders at once. The result is a quasi-static process; the large peak intensity associated with a short pump pulse can provide gain to signal photons without undergoing pulse distortion or temporal walk-off. We characterize the parametric gain available in these waveguides using optical parametric generation, where vacuum fluctuations are amplified to macroscopic intensities. When driven with pulse energies in excess of 10 pJ, we observe saturated parametric gains as large as 88 dB (146 dB/cm). The devices shown here achieve saturated optical parametric generation with orders of magnitude less pulse energy than previous techniques.