InP- and GaAs-Based Photonic Power Converters Under O-Band Laser Illumination: Performance Analysis and Comparison
Meghan N. Beattie, Henning Helmers, Gavin P. Forcade, Christopher E. Valdivia, Oliver Höhn, Karin Hinzer
Abstract
Photonic power converters (PPCs), which convert narrow-band light to electricity, are essential components in power-by-light systems. When designed for telecommunications wavelengths such as the O-band, near 1310 nm, the devices are well-suited to power-over-fiber applications. Despite the potential for very high power conversion efficiencies ( <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">$\mathbf {>50\%}$</tex-math></inline-formula> ), PPCs can be adversely affected by high-intensity nonuniform illumination conditions. In this work, we characterized two O-band PPC designs based on: high-quality InGaAsP absorber material lattice-matched to an InP substrate, and metamorphic InGaAs absorber material lattice-mismatched to a GaAs substrate, a more cost-effective and scalable alternative. We measured each device under O-band laser illumination with five beam profiles having peak-to-average ratios ranging from 2 to 11. Both devices were insensitive to the beam uniformity for input illumination with average irradiance below 2 W/cm <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">$\mathbf {^{2}}$</tex-math></inline-formula> over their 5.4-mm <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">$\mathbf {^{2}}$</tex-math></inline-formula> active areas, but exhibited better open-circuit voltages under larger, more uniform illumination profiles at higher incident powers. Measured efficiencies reached 52.8% and 48.7% for the lattice-matched and mismatched devices, respectively. Distributed circuit modeling results suggested that both lateral conduction losses and localized heating effects were responsible for the measured dependence on beam-size. Our work demonstrates the potential for O-band PPCs, presenting two highly efficient designs suitable for powering devices requiring <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">$\mathbf {\lesssim 250}$</tex-math></inline-formula> mW, with an appropriate illumination profile.