Gated detection of supercontinuum pulses enables optical probing of solid and molten silicates at extreme pressure–temperature conditions

Abstract

Gated detection of supercontinuum pulses enables optical probing of solid and molten silicates at extreme pressure-temperature conditions. -

Modelling Mie scattering in pyrolite in the laser-heated diamond anvil cell: Implications for the core-mantle boundary temperature determination

“…Once the apparent scattering coefficients are computed, they can be subtracted from the total extinction coefficient measured at high P-T by means of optical spectroscopy in a diamond anvil cell (Lobanov et al, 2016;Lobanov et al, 2017;Lobanov et al, 2020b). This will yield the temperature-dependent absorption coefficient of pyrolite and constrain its wavelengthdependence of emissivity via the Kirchhoff's law of radiation (Kirchhoff, 1860).…”

Radiometric Temperature Determination in Nongray Bridgmanite: Applications to Melting Curve and Post‐Perovskite Transition Boundary in the Lower Mantle

“…Immediately after the loading, the DAC was sealed and pressure increased to ∼50 GPa as estimated from the spectral position of the high‐frequency edge of the Raman diamond peak (Akahama & Kawamura, 2006). Once at high pressure, the sample was double‐side heated by a continuous‐wave 100 W 1070 nm YLR‐100‐AC (IPG Photonics) Yb fiber laser with a nearly flat‐top intensity distribution and beam size of ∼10 μm in the focal plane (Lobanov, Schifferle, et al., 2020). Thermal radiation was collected simultaneously from both sides by 20× Mitutoyo Plan Apochromat NIR objectives and passed through two identical spatial filters (each made of two achromatic doublets and a confocal pinhole), which allowed reducing the thermally‐probed region to a circular spot with a diameter of ∼10 μm and minimizing the systematic error in T due to radial temperature gradients.…”

“…Detailed description of this experimental setup is provided in Section II (Optical Setup) of Lobanov, Schifferle, et al. (2020). The use of the gated detector allows for precise synchronization to the probe laser pulses and is very effective in reducing the amount of thermal radiation that arrives to the ICCD, enabling optical measurements up to ∼2000 K (Lobanov et al., 2016; Lobanov et al., 2017).…”

“…The transmitted portion of the probe radiation was recorded by a gated PI-MAX 4 Intensified CCD (ICCD) detector (3 ns gate) installed on the second optical output of the SpectraPro HRS-300 spectrograph. Detailed description of this experimental setup is provided in Section II (Optical Setup) of Lobanov, Schifferle, et al (2020). The use of the gated detector allows for precise synchronization to the probe laser pulses and is very effective in reducing the amount of thermal radiation that arrives to the ICCD, enabling optical measurements up to ∼2000 K (Lobanov et al, 2016;Lobanov et al, 2017).…”

Chemical analysis of trace elements at the nanoscale in samples recovered from laser-heated diamond anvil cell experiments

“…The loaded and pressurized diamond anvil cells were then heated to the target temperature using a doublesided YAG laser at BGI and at the GeoForschung Zentrum (GFZ, Potsdam). Details of both heating systems are provided in Lobanov et al (2020) and Blanchard et al (2022), respectively. The temperature was monitored using the spectro-radiometric analysis of the thermal emission spectrum of the sample under the gray body assumption (Benedetti and Loubeyre 2004).…”