Physical mechanism on exciton-plasmon coupling revealed by femtosecond pump-probe transient absorption spectroscopy

AbstractUltrafast transient absorption spectroscopy is a powerful tool to reveal excited state dynamics in various materials. Conventionally, probe pulses are generated via bulk supercontinuum generation or (noncollinear) optical parametric amplifiers whilst pump pulses are generated separately using (noncollinear) optical parametric amplifiers. These systems are limited by either their spectral density, stability, spectral range, and/or temporal compressibility. Recently, a new intense broadband light source is being developed, the multi-plate compression, which promises to overcome these limitations. In this paper, we analyze the supercontinuum generated by a single Multiple Plate Compression system to set a benchmark for its use in the field of ultrafast pump-probe spectroscopy. We have compressed the supercontinuum to 3.3 fs using chirp mirrors alone, making it an excellent candidate for pump-probe experiments requiring high temporal resolution. Furthermore, the single light source can be used to generate both probe and pump pulses due to its high spectral density (>14.5 nJ/nm) between 490 and 890 nm. The intensity has an average shot-to-shot relative standard deviation of 4.6 % over 490 to 890 nm, calculated over 2,000 sequential shots. By using only 1,000 shot pairs, a $$\Delta T/T$$ Δ T / T noise level of $$2.6\times 10^{-4}$$ 2.6 × 10 - 4 RMS is achieved. Finally, as a proof of concept, the transient absorption spectrum of a methylammonium lead iodide perovskite film is taken, showing great signal to noise with only 1,000 shot pairs. These results show great potential for the employment of this technique in other spectroscopic techniques such as coherent multidimensional spectroscopy.

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Single 3.3-fs Multiple-Plate Compression Light Source in Ultrafast Transient Absorption Spectroscopy

10.21203/rs.3.rs-141404/v1 ◽

2021 ◽

Author(s):

Kai Chen ◽

Ronnie Tamming ◽

Justin Hodgkiss ◽

Chih-Hsuan Lu ◽

Shang-Da Yang ◽

...

Keyword(s):

Spectral Density ◽

Light Source ◽

Absorption Spectroscopy ◽

Transient Absorption ◽

Transient Absorption Spectroscopy ◽

Parametric Amplifiers ◽

Pump Probe ◽

Optical Parametric ◽

Optical Parametric Amplifiers ◽

Ultrafast Transient Absorption

Abstract Ultrafast transient absorption spectroscopy is a powerful tool to reveal excited state dynamics in various materials. Conventionally, probe pulses are generated via bulk supercontinuum generation or (noncollinear) optical parametric amplifiers whilst pump pulses are generated separately from (noncollinear) optical parametric amplifiers. These systems are limited by either their spectral density, stability, spectral range, and/or temporal compressibility. Recently, a new intense broadband light source is being developed, the multi plate compression, which promises to overcome these limitations. In this paper, we analyze the supercontinuum generated by a single multiple-plate compression system to set a benchmark for its use in the ﬁeld of ultrafast pump-probe spectroscopy. We have compressed the supercontinuum to 3.3 fs using chirp mirrors alone, making it an excellent candidate for pump-probe experiments requiring high temporal resolution. Furthermore, the single light source can be used to generate both pump and probe pulses due to its high spectral density (>14.5 nJ/nm) between 490 and 890 nm. The intensity has an average shot-to-shot relative standard deviation of 4.6% over 490 to 890 nm, calculated over 2,000 sequential shots. By using only 1,000 shot pairs, a ΔT/T noise level of 2.6 × 10−4 RMS is achieved. Finally, as a proof of concept, the transient absorption spectrum of a methylammonium lead iodide perovskite ﬁlm has been taken, showing great signal to noise with only 1,000 shot pairs. These results show great potential for the employment of this technique in other spectroscopic techniques such as coherent multidimensional spectroscopy.

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