Charge-stripe fluctuations in <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:msub><mml:mrow><mml:mi>Nd</mml:mi></mml:mrow><mml:mn>4</mml:mn></mml:msub><mml:msub><mml:mrow><mml:mi>Ni</mml:mi></mml:mrow><mml:mn>3</mml:mn></mml:msub><mml:msub><mml:mrow><mml:mi mathvariant="normal">O</mml:mi></mml:mrow><mml:mn>8</mml:mn></mml:msub></mml:math> as evidenced by optical spectroscopy

We present an investigation into the optical properties of ${\mathrm{Nd}}_{4}{\mathrm{Ni}}_{3}{\mathrm{O}}_{8}$ at different temperatures from 300 down to 5 K over a broad frequency range. The conductivity is decomposed infrared-active phonons, far-infrared band $\ensuremath{\alpha}$, mid-infrared $\ensuremath{\beta}$, and high-energy absorption edge. By comparing measured first-principles calculations response other nickelates, we find that features evident charge-stripe fluctuations. $\ensuremath{\beta}$ attributed electronic transitions between gapped Ni-${d}_{{x}^{2}\ensuremath{-}{y}^{2}}$ bands due fluctuating charge stripes, while high-frequency edge corresponds onset involving bands. Furthermore, analysis temperature-dependent spectral weight reveals ${T}^{2}$ law, which likely originate strong correlation effects.