Kenneth Marshall is a research
engineer in charge of the Liquid Crystal Materials Group at
LLE where he also serves as the chemical safety officer. Mr.
Marshall supervises students and staff in a variety of research
projects. He is quite active in the LLE Summer High School Program.His
student, Rui Wang, was an Intel Science Talent finalist in 2006
for her work on computational chemistry modelling.
Device Applications in Novel Liquid Crystal Systems
Point-Diffraction Interferometer for Microgravity Fluid Physics
(funded by NASA Glenn Research Center, Cleveland, OH). A process
for preparing “structured” substrates (those in which the reference
diffracting element are an integral part of the substrate, rather
than a separately placed element) by means of photoresist processing
was developed for the visible region, and ultimately the IR.
- Polymer LC
Flake Technology and Applications in Electronic Imaging
Polysaccharide Liquid Crystal Systems for Optical Applications
- New Materials:
A series of new chiral IR dyes with improved solubility in liquid
crystals were isolated and characterized. These new dyes show
excellent prospects for applications in sensor protection and
telecommunications in addition to inertial confinement fusion
(ICF) application areas.
Patents and Publications:
Kenneth L. Marshall and Eric Glowacki: "Photoswitchable Membrane and Method", US Patent 8,435,333, issued May 7 2013
K. L. Marshall, C. Dorrer, M. Vargas, A. Gnolek, M. Statt, and S.-H. Chen, “Photoaligned Liquid Crystal Devices for High-Peak-Power Laser Applications, (Invited)” Liquid Crystals XVI, edited by I. C. Khoo (SPIE, Bellingham, WA, 2012), Vol. 8475, Paper 84750U.
G. P. Cox, C. A. Fromen, K. L. Marshall and S. D. Jacobs, "PCLC flake-based apparatus and method,", U. S. Patent # 8,293,135 (issued 10/27/2012).
C. Dorrer, S. K.-H. Wei, P. Leung, M. Vargas, K. Wegman, J. Boulé, Z. Zhao, K. L. Marshall, and S. H. Chen, “High-Damage-Threshold Static Laser Beam Shaping Using Optically Patterned Liquid-Crystal Devices,” Opt. Lett. 36 (20), 4035–4037 (2011).
E. Glowacki, K. L. Marshall, C. W. Tang, and N. S. Sariciftci, “Doping of Organic Semiconductors Induced by Lithium Fluoride/Aluminum Electrodes Studied by Electron Spin Resonance and Infrared Reflection-Absorption Spectroscopy,” Appl. Phys. Lett. 99 (4), 043305 (2011).
K. L. Marshall, S. K.-H. Wei, M. Vargas, K. Wegman, C. Dorrer, P. Leung, J. Boulé III, Z. Zhao, and S. H. Chen, “Liquid Crystal Beam-Shaping Devices Employing Patterned Photoalignment Layers for High-Peak-Power Laser Applications” (Invited Paper), in Liquid Crystals XV, edited by I. C. Khoo (SPIE, Bellingham, WA, 2011), Vol. 8114, Paper 81140P.
Exocuticles of Beetles Contain Layers of Chitin,
a Naturally Occurring Polysaccaride that Possesses a Cholesteric
Liquid Crystal Structure
Dr. Katsuhiro Mikami is a visiting Research Associate in the laser damage testing group, funded by the Japan Society for the Promotion of Science. He joins us for a one year stay (9/13-8/14) at LLE, after receiving a Ph.D from the Graduate School of Engineering of Osaka University. He worked under Prof. K. A.Tanaka and Prof. T. Jitsuno in the Institute of Laser Engineering. The title of Dr. Mikami's dissertation was "Temperature dependence of laser-induced damage for optical materials". He will be contributing to our efforts to automate portions of our laser damage testing process. Dr. Mikami will also help us to better understand the role of environment in testing multilayer dielectric thin film coatings.
Semyon Papernov is a Scientist
at LLE. He is responsible for operating the 1-ns, long pulse laser
damage testing facility at LLE. He is also the principal operator
of the Digital Instruments Nanoscope III Atomic Force Microscope
in the Metrology Laboratory. For the past several years,
Dr. Papernov has organized and taught a course in AFM theory
and techniques to graduate students in Materials Science and
Mechanical Engineering. He is member of the International Program Committee for the Boulder Damage Symposium.
Mr. Alexei Kozlov is a research engineer in the Laser Damage Group at LLE. . He leads the short pulse 700-fs to 10-ps testing program, primarily at 1054 nm, in support of research to improve the performance of multilayer optical thin film coatings and diffractive optics. Recently he has been involved in setting up to test parts in both air and in vacuum, to understand the statistical variations in laser damage resistance caused by the extraction of water vapor from coatings
Ms. Brittany Taylor is an LLE Laboratory Engineer. She works with Mr. Kozlov in short pulse damage testing, and she assists Dr. Jacobs on a variety of other group projects. These include multilayer dielectric thin film grating cleaning processes, and the development of new devices for laser beam polarization control. Ms. Taylor is responsible for operation and training on our differential interference contrast microscopes.
Recenty Ms. Taylor became responsible for the acquisition, installation and operation of a Hinds Instruments Mueller Matrix Polarimeter.The device operates in the UV at 355-nm, and can map parts as large as 0.42-m by 0.42-m. The image on the left shows and optical rotatory power map for a series of LH and RH synthetic crystal quartz plates, stacked on each other. The scan size is ~75-mm by 75-mm, the scan resolution was set to 0.5-mm, and image acquisition took 40 h.
Papernov, Mr.Kozlov, Ms. Taylor, and visiting Research Associate Dr. Katsuhiro Mikami perform laser damage testing
in a new, dedicated laboratory facility that was recently constructed.
Damage Testing Facilities:
Testing Facility, Location: LLE Rm. 184
Operational with high reliability
Description: Frequency-converted, flashlamp-pumped
Nd: glass w/ zig-zag slab
ns; 2w 527-nm/0.8
ns; 3w 351-nm/0.6
Pulse shape: gaussian Rep rate: 8 shots
per minute Beam size: 0.6 mm
Methodology: 1-on-1 or N-on-1; damage assessed by
dark field microscopy @110x
Applications: 3w/0.6 ns
new HR/AR materials, processes, designs
high power diffraction grating concepts
Pulse Testing Facility, Location: LLE Rm.
Light Inc., Ti:sapphire + glass, chirpedpulse @ 50
1w/ 1054-nm only/0.5
ps to 10 ps; 100 ps possible w/ different compressor
Pulse shape: gaussian output from
rate: 0.1 Hz/single shot Beam
size: 1 mm
Methodology: 1-on-1, N-on-1, S-on-1; R-on-1, defect targeting; damage assessed
by dark field microscopy @110x in air / N2 / vacuum @~10-7 Torr
Applications: HR/AR film designs, beam combiners,
Diffraction gratings manufactured by reactive ion etching
Pulse Testing Facility, Location: LLE Rm. 134
Description: Nd: glass pumped Large Aperture Ring
Amplifier for 30 J
ns to 3 ns; 3w blue/1
ns to 3 ns (possibly 4-5 ns)
Pulse shape: square and Haan
Rep rate: 1 shot every 20 minutes
Beam size: 16 mm diameter (2-cm2)
Methodology: 1-on-1 or N-on-1 (with N a small number)
inspection/assessment TBD depending on spot size
Applications: 1w/3 ns
or longer square pulse - scaling for red transport: HRs/ARs
or longer square pulse - scaling for blue transport: HRs/ARs
S. Papernov, “Mechanisms of Near-Ultraviolet, Nanosecond-Pulse Laser Damage in HfO2/SiO2-Based Multilayer Coatings,” Chinese Opt. Lett. 11, S10703-6 (2013).
S. Papernov, E. Shin, T. Murray, A. W. Schmid, and J. B. Oliver, “355-nm Absorption in HfO2 and SiO2 Monolayers with Embedded Hf Nanoclusters Studied Using Photothermal Heterodyne Imaging,” Laser-Induced Damage in Optical Materials: 2012, edited by G. J. Exarhos, V. E. Gruzdev, J. A. Menapace, D. Ristau, and M. J. Soileau, (SPIE, Bellingham, WA, 2012), Vol. 8530, Paper 85301H.
S. Papernov, A. Tait, W. Bittle, A. W. Schmid, J. B. Oliver, and P. Kupinski, “Near Ultraviolet Absorption and Laser Damage in HfO2 Films Studied Using AFM and Photothermal Heterodyne Imaging With Submicrometer Resolution,” J. Appl. Phys. 109, p. 113106 (2011).
J. B. Oliver, P. Kupinski, A. L. Rigatti, A. W. Schmid, J. C. Lambropoulos, S. Papernov, A. Kozlov, J. Spaulding, D. Sadowski, Z. R. Chrzan, R. D. Hand, D. R. Gibson, I. Brinkley, and F. Placido, “Large-Aperture Plasma-Assisted Deposition of Inertial Confinement Fusion Laser Coatings,” Appl. Opt. 50, C19–C26 (2011).
S. Papernov, A. Tait, W. Bittle, A. W. Schmid, J. B. Oliver, and P. Kupinski, “Submicrometer-Resolution Mapping of Ultraweak 355-nm Absorption in HfO2 Monolayers Using Photothermal Heterodyne Imaging,” in Laser-Induced Damage in Optical Materials: 2010, edited by G. J. Exarhos, V. E. Gruzdev, J. A. Menapace, D. Ristau, and M. J. Soileau (SPIE, Bellingham, WA, 2010), Vol. 7842, Paper 78420A.
crater produced by 351nm pulse in SiO2 thin film
doped with 8nm gold particles.
Alexander Maltsev is the
supervisor of the LLE Optical Fabrication Shop. As a master
optician, he is responsible for carrying out unique manufacturing
projects in support of LLE and other University research programs.
Mr. Maltsev turns out precision, one-of-a-kind optical elements
from specialty glasses and crystals.
Mr. Mike Kaplun is a Lab Tech V working in the LLE Optical Fabrication
Shop. He assists Mr. Maltsev in producing optics for customers and is fully trained to manage the Shop and to operate all equipment in the facility in Mr. Maltsev's absence.
Products produced in The Optical Fabrication Shop include prisms, etalons, and other specially shaped optics.
Mr. Maltsev and Mr. Kaplun maintain and operate two large continuous polishing machines
used to polish up to 300 mm diameter flats to lambda/20
precision. The Shop also has double sided grinding and polishing machines that are capable of producing large batch quantities of small flats.
spring, Mr. Maltsev teaches the laboratory sessions for Optics
443: Optical Fabrication and Testing, a graduate elective offered
through The Institute of Optics. In this course, students learn
how to hand-fabricate and test precision optics, starting from
a glass block.