Kenneth G. Libbrecht --Home
Page
--Professor of Physics at Caltech
--and Chairman of the Physics Department
| Current Research Interests |
 Advanced detector development for the Laser Interferometer
Gravitational-wave Observatory (LIGO). The LIGO project is aimed at detecting
and studying gravitational-wave signals from violent astrophysical events, such as
supernovae or coalescing neutron stars and black holes. For more information on all
aspects of the LIGO project, see the LIGO web
site. My work in LIGO is currently focused in two areas. The first is
an instrument called the Thermal Noise Interferometer (TNI), which is a test-bed
suspended interferometer at Caltech. We are using this instrument to examine
fundamental and technical sources of noise that limit the sensitivity of LIGO. Our
second undertaking is a photothermal interferometer for measuring the properties of
optical coatings used in the LIGO detectors. |
 The Physics of Crystal Growth and Pattern Formation in Ice. This
project is essentially a case study of the growth of ice crystals from the vapor phase,
the purpose of which is to better understanding pattern formation in nonlinear
nonequilibrim systems. The diverse morphologies seen in snow crystals are largely
due to the bizarre temperature dependence of ice crystal growth rates, a phenomenon that
was discovered 75 years ago and remains unexplained to this day. We have been making
precise measurements of the growth rates of the different facets of ice crystals under
controlled conditions to gain insights into the temperature dependent molecular structure
of the ice surface and how it affects crystal growth. Pictures (and movies) of
growing snow crystals can be found at my Snow Crystals page. |
 Electrically Modified Crystal Growth and Structure Formation. When
a high voltage is applied to a growing crystal, a number of electrophysical and
electrochemical effects can conspire to produce novel growth behaviors, in particular the
growth of nanoscale needle-like structures. We are investigating the electrically
modified growth and morphology of a variety of materials in order to better understand the
mechanisms of needle formation, as well as to explore possible applications. |
 Tunable
Diode Lasers in Physics Education. Grating-stabilized tunable diode lasers can
provide an inexpensive and versatile source of laser light for doing simple experiments in
atomic, molecular, and optical physics. We have developed several such experiments
for the undergraduate laboratory, which can be seen at the Ph76 website. We have also been
working with TeachSpin
to produce a commercial tunable diode laser system aimed at the undergraduate education
market, which should be available sometime in early 2004. |
| Some Past Lives |
  Helieseismology
and the Large-Scale Structure of the Sun. Convective motions near the solar
surface generate acoustic waves that resonate inside the Sun, resulting in global
oscillation modes with periods around five minutes. We made extensive measurements
of these global modes in the late 1980s at Big Bear Solar Observatory, recording Doppler
images of the entire solar disk each minute for many months on end. Analysis of
these tens of thousands of images (back when a GByte of disk space was something special!)
allowed us to measure the solar mode frequencies to unprecedented accuracy. By
examining the mode frequencies and amplitudes, as well as the frequency splittings of mode
multiplets, information about the interior structure and dynamics of the Sun could be
extracted, including a measure of the interior rotation rate of the Sun. |
 Laser
Cooling and Trapping of Individual Atoms. We built laser-cooled magneto-optical
atom traps in the early 1990s that could capture and observe individual cesium atoms.
This technology was used to investigate the dynamics of atom trapping in the
low-atom-number limit. We also investigated the use of microfabricated planar
current structures for making microscopic magnetic atom traps. |
Courses and Education
Ph77 -- Advanced Physics
Laboratory. Click here
for course information, including downloadable descriptions of the individual
labs.
CV and Publications
Here are
links to a curriculum vitae
and a list of
publications.
Contact Information
E-mail: kgl@caltech.edu
Phone: 626-395-3722
Fax:
626-395-3802
Address: Physics
Department, Caltech 264-33, Pasadena, CA 91125 page views since February 1, 1999