1995
As an interim project at UC Irvine, I assembled an ultrafast Ti:sapphire laser based on the design of Murnane and Kapteyn for application to time-resolved spectroscopy of condensed matter.
1992-1994
I was hired initially to install a new free-electron laser (FEL) which would become the new workhorse of the Stanford SCA/FEL user facility. I designed and installed the optics and vacuum systems and managed the entire project. When I was hired, the project was in its infant stages, and I took responsibility for bringing the project to its current operational state. Management included the use and oversight of a vacuum designer, technicians, and occasionally graduate and undergraduate students and other post-docs. Optics included dual alignment systems, complete resonator design, and transport (through 40 meters to diagnostics described below), all integrated with the vacuum and electron beam systems. I designed the system to lase at a wavelength between 3 and 18 microns and made it relatively easy to operate and maintain (a rarity for FELs). This project had a total budget of $150,000 and was completed over about 18 months.
Shortly after I was hired, I was assigned the additional responsibility for the user facility laser diagnostics (in addition to the FEL installation above). I examined the needs of our eclectic and diverse users and designed a completely new system which satisfied all of the users' demands. This system includes one "in" and one "out" reflective telescope to deliver the 3-18 µm FEL beam to users along a 30 m path, a variety of beamsplitters for pick-offs, pyro-electric quadrant detectors to monitor beam steering, 1 MHz and 1 GHz HgCdTe general purpose detectors to observe both micro- and macro-pulse behavior of FEL beam, wavelength stabilization loop (optics branch: monochromator with linear array MCT detector at exit plane), non-standard acousto-optical modulator/noise eater feedback loop, crossed-beam doubling autocorrelator operating with Å 7% of total beam, alignment HeNe for downstream users with documented procedure to co-align with FEL beam using pyro quads, remote steering of output telescope by users, recommended standardization of all experimental data acquisition and control (not just diagnostics) to the "LabView" platform. This project had a budget of $100,000.
As there was no optics specialist in the group when I was hired, I took responsibility to teach the student proper techniques and to consult on most of the user experiments. One such example was helping to design a new pulse selection and pump/probe layout for physical chemistry and material science studies. I was also heavily involved in experimental design for many biophysics and biomedical projects.
My most recent experiments apply "frequency resolved optical gating" (FROG) to characterize the FEL micropulses, and to apply it to the study of linear effects in materials. I learned of the FROG technique from its use with visible and near IR lasers and I planned, developed, and executed the experiment on the FEL, the first time such measurements have been made either on an FEL or in the mid-IR.
I am directly involved in nonlinear studies of quantum well devices and novel nonlinear crystals in collaboration with Martin Fejer of the Applied Physics department, as well as Philippe Fauchet of the Optics center at University of Rochester. I have also assisted with synchronization of a mode-locked Ti:Sapphire laser with the FEL, both as a diagnostic for the FEL, and for future use in two color pump/probe experiments on biologically significant molecules (in collaboration with Steve Boxer of the Chemistry department). We are beginning a collaboration with Stuart Kim from the department of biomedicine to study the activation mechanisms of the "heat shock gene" in nematodes and cell cultures. I recently derived a new type of "Radon transform" (most commonly used in biomedical imaging) to invert a set of electron beam energy spectra to recover the shape of our linac pulses. These projects and others involve cooperating with researchers from many different scientific fields and from several research institutes.
Dissertation (1986-91):
Title: Three-dimensional Guiding Effects in a Free Electron Laser
The dissertation includes autocorrelation experiments on the MKIII free-electron laser at the Stanford Photon Research Laboratory (SPRL) to determine some of the three-dimensional characteristics of the picosecond laser pulses as a function of accelerator and laser operating parameters. The results of these measurements are compared with 4-D simulations provided by Los Alamos National Labs.
1984-91:
Research work prior to the dissertation (at SPRL) included creation of a new technique for construction of a high quality magnetic wiggler (the heart of a free-electron laser), characterization, installation, and operation of the completed laser. Done in parallel with the dissertation, the MOPA project (Master Oscillator-Power Amplifier) was the first set of experiments to demonstrate the possibility of amplifying the output of one FEL with another. I designed the complex and remote controlled optics systems necessary to transport the laser beam from the oscillator to the amplifier. I also constructed the hardware, and wrote and debugged the computer software for control of the above optics systems and for the control and data acquisition for experiments. I developed familiarity with the small linear accelerator which supplied the electron beam for the lasers.
This work involved cooperation with other people, both physicists and non-physicists, from within the university and from private industry (Rocketdyne division of Rockwell International), and national labs.
Senior year 1983-4:
Research in senior year on the development of anti-reflection layers on scintillator crystals. The work was performed using a Van de Graff accelerator, an alpha emitter, and chemical etching techniques.
Summers 1982-4:
Research assistant at the Air Pollution Health Effects Laboratory (APHEL) at UC Irvine (Community & Environmental Medicine). Work included data reduction, some programming, work with animals, and interaction with the media.
1981-93:
Voluntary and paid tutoring in undergraduate math and physics, with emphasis on developing lecture organization and presentation skills. I have an excellent rapport with both graduate and undergraduate students.
1977-95:
Private tutoring in high school math and science including all levels of advancement and difficulty.