60 beam OMEGA laser has 300 liquid crystal optical elements
located throughout the IR portion of the system. These precision
optics are manufactured entirely in-house within the Optics Manufacturing
(OMAN) group in dedicated clean rooms. There are two component types:
liquid crystal circular polarizers (LCP), and liquid crystal waveplates
(LCW). Both are manufactured in apertures of 100 mm to 200 mm.
provide back-reflection protection for the IR portion of the laser
system. An LCP consists of a ~18 µm thick chiral nematic fluid
layer, tuned to exhibit selective reflection of left handed circularly
polarized light at a wavelength of 1054 nm, and sandwiched between
two optical quality, AR coated glass flats. Once installed in a
beam line, an LCP resets the polarization contrast of the transmitted
laser beam to ~500:1. It cleans up the quality of the beam polarization,
removing the effects of residual stress-birefringence from laser
amplifier glass and other optics. Each LCP also acts as an optical
diode, or optical isolator. Laser radiation, back reflected from
misaligned surfaces in the beam path, is blocked from propagating
back up the beam line.
are nematic fluids whose birefringence and fluid layer thickness
have been precisely adjusted for either a quarter-wave or a half-wave
in retardance at 1054 nm. Elements are located in areas of the system
where the laser beam linear polarization requires reorientation
for beam splitting, or they are used to convert between linear and
circular polarization for propagation through laser rod amplifiers.
of research include laser interactions with liquid crystals, design
and synthesis of laser damage resistant liquid crystal compounds,
and alignment of liquid crystals.
M. Korenic, S. D. Jacobs, J. K. Houghton, A. Schmid, and F. Kreuzer,
"Nematic Polymer Liquid-Crystal Wave Plate for High-Power Lasers
at 1054 nm," Appl. Opt. 33, 1889-1899 (1994).
Schmid, S. Papernov, Z.-W. Li, K. Marshall, T. Gunderman, J.-C.
Lee, M. Guardalben, and S. D. Jacobs, "Liquid-Crystal Materials
for High Peak-Power Laser Applications," Mol. Cryst. Liq.
Cryst. 207, 33-42 (1991).
Lee, A. Schmid, and S. D. Jacobs, "Effects of Anchoring Under
Intense Optical Fields in a Cholesteric Liquid Crystal," Mol.
Cryst. & Liq. Cryst. 166, 253-265 (1989).
D. Jacobs, K. A. Cerqua, K. L. Marshall, A. Schmid, M. J. Guardalben,
and K. J. Skerrett, "Liquid-Crystal Laser Optics: Design, Fabrication,
and Performance,"J. Opt. Soc. Am. B 5, 1962-1979