A5046018402- Astrophysical Phenomena and Observations
- Advanced X-ray Imaging Techniques
- Optical Coatings and Gratings
- Advanced Surface Polishing Techniques
- Advanced Measurement and Metrology Techniques
- Adaptive optics and wavefront sensing
- X-ray Spectroscopy and Fluorescence Analysis
- Optical measurement and interference techniques
- Photonic and Optical Devices
- Astronomical Observations and Instrumentation
- Advancements in Photolithography Techniques
- Optical Systems and Laser Technology
- Particle Detector Development and Performance
- Particle Accelerators and Free-Electron Lasers
- Laser Material Processing Techniques
- Stellar, planetary, and galactic studies
- Calibration and Measurement Techniques
- Astronomy and Astrophysical Research
- Nuclear Physics and Applications
- High-pressure geophysics and materials
- Crystallography and Radiation Phenomena
- Solar and Space Plasma Dynamics
- Force Microscopy Techniques and Applications
- Superconducting and THz Device Technology
- Nanofabrication and Lithography Techniques
Massachusetts Institute of Technology
2016-2025
Kavli Institute for Particle Astrophysics and Cosmology
2014-2024
Vassar College
2010-2023
Kavli Energy NanoScience Institute
2016-2021
Moscow Institute of Thermal Technology
2020
IIT@MIT
2020
K Lab (United States)
2018
Association for Language Learning
2009
Stanford University
2004
Harvard University
1997-2004
Lynx, one of the four strategic mission concepts under study for 2020 Astrophysics Decadal Survey, provides leaps in capability over previous and planned x-ray missions synergistic observations 2030s to a multitude space- ground-based observatories across all wavelengths. Lynx orders magnitude improvement sensitivity, on-axis subarcsecond imaging with arcsecond angular resolution large field view, high-resolution spectroscopy point-like extended sources 0.2- 10-keV range. The architecture...
MARX is a portable ray-trace program that was originally developed to simulate event data from the trans- mission grating spectrometers on-board Chandra X-ray Observatory (CXO). has since evolved include detailed models of all CXO science instruments and been further modified serve as an simulator for future observatory design concepts. We first review number applications demonstrate roles such could play throughout life mission, including its calibration, production input products...
The analysis of many systems in optical communications and metrology utilizing Gaussian beams, such as free-space propagation from single-mode fibers, point diffraction interferometers, interference lithography, would benefit an accurate analytical model beam propagation. We present a full vector by using the well-known method angular spectrum plane waves. A is assumed to traverse charge-free, homogeneous, isotropic, linear, nonmagnetic dielectric medium. representation, its form, applied...
Lynx is a concept under study for prioritization in the 2020 Astrophysics Decadal Survey. Providing orders of magnitude increase sensitivity over Chandra, will examine first black holes and their galaxies, map large-scale structure galactic halos, shed new light on environments young stars planetary systems. In order to meet science goals, telescope consists high-angular resolution optical assembly complemented by an instrument suite that may include High Definition X-ray Imager,...
Arcus will be proposed to the NASA Explorer program as a free-flying satellite mission that enable high-resolution soft X-ray spectroscopy (8-50) with unprecedented sensitivity – effective areas of >500 sq cm and spectral resolution >2500. The key science goals are (1) determine how baryons cycle in out galaxies by measuring effects structure formation imprinted upon hot gas is predicted lie extended halos around galaxies, groups, clusters, (2) black holes influence their surroundings...
Accurate fabrication of high-aspect ratio (HAR) structures in applications from semiconductor devices to x-ray observatories is essential for their optimal performance because directly depends on structure. High-efficiency critical-angle transmission (CAT) gratings enable high-resolution spectroscopy astrophysics, but only ideal when certain performance-critical parameters, like the bar tilts introduced during deep reactive-ion etching, are tuned precise values. Traditional measurement...
Metrology is the science and engineering of measurement. It has played a crucial role in industrial revolution at milli-inch length scale semiconductor micrometre scale. often proclaimed that we are standing threshold another revolution, brought by advent maturing nanotechnology. We argue for nanotechnology to have similarly revolutionary effect metrology infrastructure below nanometre instrumental yet be developed. This paper focuses on dimensional metrology, which concerns itself with...
The authors report a silicon-on-insulator (SOI) process for the fabrication of ultrahigh aspect ratio freestanding gratings high efficiency x-ray and extreme ultraviolet spectroscopy. This new grating design will lead to blazed transmission via total external reflection on sidewalls x rays incident at graze angles below their critical angle (about 1°–2°). critical-angle (CAT) combines alignment figure insensitivity with broadband diffraction efficiency, which traditionally has been domain...
The Marshall Grazing Incidence X-ray Spectrometer (MaGIXS) sounding rocket experiment launched on July 30, 2021 from the White Sands Missile Range in New Mexico. MaGIXS is a unique solar observing telescope developed to capture spectral images, 6 - 24 Angstrom wavelength range, of coronal active regions. Its novel design takes advantage recent technological advances related fabricating and optimizing optical systems as well breakthroughs inversion methodologies necessary create spectrally...
Volume x-ray gratings consisting of a multilayer coating deposited on blazed substrate can diffract with very high efficiency, even in orders if diffraction conditions in-plane (grating) and out-of-plane (Bragg multilayer) are met simultaneously. This remarkable property, however, depends critically the ability to create structure near atomic perfection. In this Letter we report method produce these structures. We measurements that show, for 5000l/mm grating diffracting third order,...
We report on measurements of the diffraction efficiency 200-nm-period freestanding blazed transmission gratings for wavelengths in 0.96 to 19.4 nm range. These critical-angle (CAT) achieve highly efficient blazing over a broad band via total external reflection off sidewalls smooth, tens nanometer thin ultrahigh aspect-ratio silicon grating bars and thus combine advantages x-ray with those more conventional gratings. Prototype maximum depths 3.2 6 μm were investigated at two different blaze...
NASA's <i>Chandra</i> X-ray Observatory continues to provide an unparalleled means for exploring the high-energy universe. With its half-arcsecond angular resolution, studies have deepened our understanding of galaxy clusters, active galactic nuclei, galaxies, supernova remnants, neutron stars, black holes, and solar system objects. As we look beyond <i>Chandra</i>, it is clear that comparable or even better resolution with greatly increased photon throughput essential address ever more...
We report on the measurement of fringe-to-substrate phase error in our Nanoruler system. This system utilizes scanning beam interference lithography to pattern and measure large-area, nanometer-accuracy gratings that are appropriate for semiconductor integrated opto-electronic metrology. present Nanonruler’s metrology is based digital frequency synthesizers, acousto-optics, heterodyne sensing. It used assess placement stability accuracy feedback signals. The can perform measurements real...
The microscopic structure of Langmuir films derivatized gold nanoparticles has been studied as a function area/particle on the water surface. molecules (AuSHDA) consist particles mean core diameter D approximately 22 angstroms that have stabilized by attachment carboxylic acid terminated alkylthiols, HS-(CH2)15-COOH. Compression film results in broad plateau finite pressure surface versus isotherm is consistent with first-order monolayer/bilayer transition. X-ray specular reflectivity (XR)...
Diffraction gratings are ubiquitous wavelength dispersive elements for photons as well subatomic particles, atoms, and large molecules. They serve enabling devices spectroscopy, microscopy, interferometry in numerous applications across the physical sciences. Transmission required that demand high alignment figure error tolerances, low weight size, or a straight-through zero-order beam. However, particles often strongly absorbed upon transmission, e.g., increasingly important extreme...
High-resolution spectroscopy of astrophysical sources is the key to gaining a quantitative understanding history, dynamics, and current conditions cosmos. A large-area (> 1,000 cm<sup>2</sup>), high resolving power (R = λ/Δλ> 3000) soft x-ray grating spectrometer (XGS) that covers lines C, N, O, Ne Fe ions ideal tool address number high-priority science questions from 2010 Decadal Survey, such as connection between super-massive black holes large-scale structure via...
Thin silicon dioxide films have been studied as a function of deposition parameters and annealing temperatures. Films were deposited by tetraethoxysilane (TEOS) dual-frequency plasma enhanced chemical vapor with different time interval fractions high-frequency low-frequency depositions. The samples subsequently annealed up to 930 °C investigate their stress behavior. that in dominated found tensile residual after at temperatures higher than 800 °C. can be controlled slightly changing the...
Abstract Arcus is a proposed Explorer Class soft X-ray grating spectrometer. It aims to explore cosmic feedback by mapping hot gases within and between galaxies galaxy clusters characterizing jets winds from supermassive black holes investigate the dynamics of protoplanetary disks stellar accretion. features 12 m focal-length grazing-incidence silicon pore optics (SPO) developed for Athena mission. Critical-angle transmission (CAT) gratings efficiently disperse high diffraction orders onto...
We are developing a Scanning Beam Interference Lithography (SBIL) system. SBIL represents new paradigm in semiconductor metrology, capable of patterning large-area linear gratings and grids with nanometer overall phase accuracy. Realizing our accuracy goal is major challenge because the interference fringes have to be locked moving substrate spatial errors while period has stabilized approximately one part per million. In this paper, we present review design, report recent progress towards...
Efficiency measurements of a grazing-incidence diffraction grating in the off-plane mount were performed using polarized synchrotron radiation. The had 5000 grooves/mm, an effective blaze angle 14 degrees, and was gold coated. efficiencies two polarization orientations (TM TE) measured 1.5-5.0 nm wavelength range compared with calculated PCGrate-SX code. TM TE differ, offering possibility performing unique science studies astrophysical, solar, laboratory sources by exploiting sensitivity grating.
The authors report on the fabrication of 200nm period blazed transmission gratings silicon-on-insulator (SOI) wafers. These critical angle (CAT) require 3–5μm tall freestanding grating bars with a very high aspect ratio (&gt;100) and smooth sidewalls. In order to meet challenging geometrical requirements, they modified improved our previously reported process for CAT prototype 574nm period. They have used potassium hydroxide (KOH) solutions fabricate ⟨110⟩ SOI KOH etching was minimize...
The authors present a breakthrough multistage dry-etch process to create 100 nm half-pitch gratings in silicon with depths up 6 μm. Interference lithography was used pattern an optically matched stack of materials form 400-nm-thick oxide hard-mask. then mask the subsequent deep reactive-ion etching silicon. In this article, describe their grating patterning, transfer, and etch processes, progress toward combining technique coarser scale steps designed integrated mechanical support structure...
SMART-X is a mission concept for 2.3 m<sup>2</sup> effective area, 0.5" angular resolution X-ray telescope, with 5' FOV, 1" pixel size microcalorimeter, 22' FOV imager, and high-throughput gratings.
A fully integrated fabrication process has been developed to fabricate freestanding, ultrahigh aspect ratio silicon gratings with potassium hydroxide (KOH)-polished sidewalls. The are being for wavelength-dispersive, soft x-ray spectroscopy on future space telescopes. For this application, the grating needs have a large open-area fraction and smooth sidewalls (roughness &lt; 1 nm) maximize efficiency. prototype fabricated presented here tested synchrotron beamline demonstrated an...
We introduce a novel method for correcting distortion in thin silicon substrates caused by coating stress. Thin substrates, such as lightweight mirrors x-ray or optical imaging, and semiconductor wafers flat panel are easily distorted stress film coatings. report new stress-induced which utilizes micro-patterned oxide layer on the back side of substrate. Due to excellent lithographic precision patterning process, we demonstrate compensation control ~0.2%. The proposed process is simple...