Optic Technologies Enabling Fusion Ignition (eBook)

Tayyab I. Suratwala, C. Wren Carr, Christopher J. Stolz (Herausgeber)

eBook Download: EPUB

2025
1107 Seiten
Wiley (Verlag)
978-1-394-26825-2 (ISBN)

Infos

A powerful and up-to-date desk reference for advancements in optic technologies for high energy lasers

In Optic Technologies Enabling Fusion Ignition, a team of veteran optics and laser specialists deliver an expert summary of optic manufacturing technologies, laser-induced optic damage reduction technologies, and optic repair & recycle technologies. The authors explore the fundamental scientific phenomena and how they have driven the development of optic technologies as well as the process of transitioning from scientific discovery to large-scale production.

The book combines examinations of improving overall optic performance, optic survivability, and laser performance. It also covers novel bulk material developments, yield processing improvement methods, novel metrologies, and advancements in increasing laser-induced damage resistance.

Readers will also find:

• A thorough introduction to the details of optics recycle loop technologies, including the refurbishment and repair of laser-induced damaged optics
• Comprehensive explorations of advancements in optical fabrication and post-processing reducing laser damaging surface precursors
• Practical discussions of the fundamental physics of laser-matter interactions related to laser-induced damage
• Complete treatments of laser-induced damage data management, the use of online shadow blockers, and novel optics metrologies

Ideal for optical and laser scientists, engineers, and fabricators of optical materials and components, Optic Technologies Enabling Fusion Ignition is also a valuable resource for graduate students interested in optics, as well as high-energy and high-power laser research.

Tayyab I. Suratwala, PhD, is the Program Director for Optics and Materials Science & Technology (OMST) in the NIF & Photon Science Directorate at Lawrence Livermore National Laboratory (LLNL). He has 28 years of experience in optical fabrication and materials processing.

C. Wren Carr, PhD, is a Group Leader for Science & Technology for OMST at LLNL. He has 25 years of experience in the field of laser-induced damage in optical materials.

Christopher J. Stolz is the former Group Leader for Optics Supply for OMST at LLNL. He has 36 years of experience in high fluence multilayer optical coatings and optical fabrication.

Textauszug

List of Figures

Figure 1.1

(a) Fusion output or yield in MJ as a function of time, where each bar represents a single laser shot using a DT target; (b) neutron image of the “Sun” created during the December 5, 2022, ignition shot.

Figure 1.2

(top-left) Photo of typical ICF indirect drive target; (top-middle) photo of high-density carbon (HDC) capsule (ablator) (∼2 mm diameter); (top-right) X-ray image of the capsule showing the doped layer and frozen crystalline layer of DT; (bottom) schematic showing the process of inertial confinement fusion using an indirect drive target.

Figure 1.3

(a) Schematic of the National Ignition Facility (NIF) laser; (b) configuration of the NIF large optics in a single NIF beamline; (c) photos of the various types of NIF large optics.

Figure 1.4

NIF vendor partners that made the bulk material (blanks) or fabricated (finishing and coating) the large NIF build and operational optics.

Figure 1.5

Timeline of important optic technologies developed since the mid-1990s for NIF.

Figure 1.6

(a) An initiated laser damage site on the exit surface of a fused-silica optic ∼5 μm in diameter (39); (b) damage site diameter as a function of laser shots at nominal NIF 1.8 MJ shot fluences at 3ω.

Figure 1.7

Laser damage areal density on a fused-silica optic surface as a function of 3ω laser fluence. The lines represent the quality level at various times. The shaded region indicates the relative fluence distribution for a 1.8 MJ NIF laser shot.

Figure 1.8

Schematic illustrating the optics recycle loop strategy used on NIF.

Figure 1.9

(left) Schematic showing the final optics in a single beamline on NIF with arrows pointing to the wedged focus lens (WFL) and grating debris shield (GDS), which dominate the optics recycle loop; (right) photos showing some of the major steps in the optics recycle loop (ordered left to right and then top row to bottom row).

Figure 1.10

Rate of optics exchanges of major large optics components from NIF. The solid lines with solid data points represent the exchange rates for optics in the in-house optics recycle loop, namely the WFL and GDS optics.

Figure 1.11

The NIF system level parameter (RLoop), describing the overall recycle loop exchange rate (and hence damage rate) on the WFL/GDS optics as a function of time. For a typical LGsys use rate on NIF, maintaining RLoop below 100 optic exchanges/LG is required.

Figure 1.12

Evolution of the distribution of the high-fluence beam shots on NIF for various fiscal years.

Figure 2.1

Schematic representation of NIF. The optics are housed in the Laser Bays, where amplification occurs; the Switchyard, where mirrors steer the beams toward the Target Chamber; and the Target Bay, where polarization rotation, frequency conversion, and beam focusing occur to deliver light to the target.

Figure 2.2

A statistically based specification allowed a small fraction of optics to exceed specification. This minimizes reworking costs, because the large number of optical surfaces in a beamline result in an average performance that is better than specification.

Figure 2.3

Schematic representation of the optics and environments on NIF.

Figure 2.4

Energy levels for Nd3+ evolving from the 4f3 configuration, showing coulombic (Hcoul), spin±orbit coupling (HSO), and crystal field (HCF) interactions. Also shown is the measured Nd-absorption cross section in a typical metaphosphate-glass host (24) and the relative output intensity for a xenon flashlamp and laser-diode pump source. The laser transition of interest (1053 nm) is from the metastable 4F3/2 state to the 4I11/2 terminal level. The wavy lines denote rapid non-radiative (multi-phonon) transitions. The energies shown are relative to the 4I9/2 ground state.

Figure 2.5

Four mounted laser-glass slabs ready for insertion into one of the amplifier locations on NIF (left) and an artist's representation of the PA, consisting of a bundle of eight beams with five amplifier slabs in each beamline (right).

Figure 2.6

Spatial filters have the dual purpose of filtering out high-spatial-frequency optical noise leading to beam contrast that occurs during amplification and serves as a relay telescope that minimizes contrast in the final optics assembly, where the laser-induced damage rate of the optics limit the total laser energy delivered onto the target.

Figure 2.7

Depiction (left) of how four WFLs, used to focus a quad of beamlines onto a target in the center of the NIF Target Chamber, are essentially segments of two pairs of focusing lens. The actual optics (right) are manufactured with small-tool finishing technologies, requiring extensive metrology to prevent surface ripples.

Figure 2.8

The NIF deformable mirror and wavefront control system bend the mirror surface so that the wavefront of the laser improves as it propagates through optics with low-order wavefront errors, leading to an improved Strehl ratio that results in improved beam focus at the center of the Target Chamber.

Figure 2.9

Top graph charts NIF transport-mirror dichroic coatings, designed to efficiently reflect the forward-propagating 1ω laser and a 375 nm alignment beam while suppressing reflection of target backscatter into the laser. The final two transport mirrors (LM7-8 in the bottom image) are solarized to absorb target backscatter and prevent laser-induced damage to the mounting hardware. The optic on the left is solarized, while the optic on the right is not.

Figure 2.10

Beam dumps installed to capture 3ω ghost reflections from the final optics to prevent laser-induced damage to the final transport mirror.

Figure 2.11

Gas knives are installed on upward-facing transport mirrors to remove particulates that can lead to laser-induced damage, thus extending their operational lifetime. At left is a schematic of the gas knives for a quad of transport mirrors; at right, a quad of upward-facing mirrors installed with gas-knife hardware.

Figure 2.12

Photo and cross-sectional schematic of the plasma electrode Pockels cell (PEPC).

Figure 2.13

Two frequency-conversion crystals are used to convert the 1ω laser to a 3ω laser with modest residual 1ω and 2ω light also transmitted into the Target Chamber.

Figure 2.14

CPPs are used on NIF to create an enlarged and uniform spot size on target.

Figure 2.15

NIF phase plates (top) are manufactured by magnetorheological finishing, a small-tool polishing process, to create a continuous (smooth) topography necessary for the various spot sizes (bottom) desired by experimentalists.

Figure 2.16

Installation of two DDS cassettes, each containing five DDS optics per NIF beamline.

Figure 2.17

Grating structure (left) etched into the exit surface of a GDS, which is subsequently overcoated with a sol–gel AR coating to minimize transport loss onto the target and debris caused by ghost reflections off the GDS. To the right is a photo of a GDS optic.

Figure 2.18

Pulse-compression gratings are used on the ARC diagnostic laser to create a high-energy ultra-short pulse to backlight targets during compression.

Figure 2.19

Pulse-compression gratings are etched into a thick silica layer on top of a multilayer dielectric mirror.

Figure 2.20

The exposure laser beams in the holographic exposure apparatus illuminate the 1100-mm aperture collimation lens to expose the large diffractive gratings.

Figure 2.21

Large reactive ion beam system is capable of etching submicron features into substrates as large as...

Produkt-Details

• Erscheint lt. Verlag: 10.7.2025
• Sprache: englisch
• Themenwelt: Naturwissenschaften ► Chemie
• Themenwelt: Technik ► Maschinenbau
• Schlagworte: Laser Performance • optical fabrication • optic laser-induced damage reduction technologies • Optic manufacturing technologies • optic recycle loop technologies • optics manufacturing • optics performance • optics recycling • optic survivability
• ISBN-10: 1-394-26825-4 / 1394268254
• ISBN-13: 978-1-394-26825-2 / 9781394268252