Expert in Physics, Optics, and Lasers
Expert has an extensive background in classical and modern physics. His major sub-fields have been optics and electrical phenomena. He has treated subjects such as thermal runaway in high power, high frequency, ferrite transformer cores; the effects of gas fill on proportional counter performance at high counting rates; field theory of traveling-wave tubes; cooling of lasers; numerical calculation of electric fields inside a Pockels cell (electro-optical shutter crystal) with a method suitable for other mixed boundary value problems; and heating of materials subject to Q-switched laser pulses.
These fundamental principles repeatedly turn up in almost every field of science and technology. Expert has applied them to the instability of rotating shafts (for rotating laser Q-switches); the design of rotationally vibrating Q-switches; and the behavior of cast flylines and how to improve casting performance. He is familiar with Lagrangian and variational methods for the solution of mechanics problems. Because the same variational methods apply in many fields of physics, he has been able to apply variational methods to wave propagation in nonuniform media for electromagnetic and acoustic problems.
Expert is a Registered Professional Engineer (electrical branch) in California. He is especially well-grounded in circuit theory of the type used in most of electrical engineering. Before entering the new field of lasers, he worked on radar modulators and signal processing, vacuum tubes, and analog and digital circuitry. These skills were further developed when he worked on lasers because electronic circuitry comprises a large portion of a laser system. Among his projects were high-power-factor power supplies for charging capacitors, including development of a monocyclic transformer for a constant AC voltage to a constant DC current charging supply; phase controlled power supply; modification of a (sugar) polarimeter for remote sensing using a laser light source; a radio frequency driver for an acousto-optic modulator; and a 25-kilovolt pulse driver for a CO2 laser. Expert's efforts have contributed to the Strategic Defense Initiative.
Expert has worked on the development and application of ruby, neodymium, CO2, injection lasers, a uranium doped laser, and associated nonlinear optical techniques. Recently, he has worked on a rangefinder using simulated Raman conversion of 1.06 micrometer radiation to an eyesafe radiation at a wavelength of 1.54 micrometer. He has helped develop radio frequency drivers for waveguide CO2 lasers, analyzed mode selection in such lasers, and designed optical (infrared) systems based upon Gaussian beam propagation. He developed a laser using a passive dye Q-switch. By solving the differential equations describing dye Q-switched operations, he discovered a number of problems that were surmountable with proper foresight. These lasers include those that do not reach maximum gain early during their pulse build-up. He has simulated the growth of laser pulses in resonators, and determined how modes get selected during laser buildup as a function of resonator quality. Expert has worked on laser system performance prediction in various atmospheric conditions and performed calculations to set laser safety standards.
Electromagnetic radiation, whether in the radio frequency, infrared, visible, ultraviolet, or X-ray portion of the spectrum, is the basis of most of Expert's work.
Aspects of geometrical and physical optics, excluding detailed lens design, have been at the heart of Expert's career. He has made radiometric and photometric calculations to predict optical system performance. He has worked with infrared and visually clear materials. He has used photography and densitometry to measure optical performance. Expert has investigated the properties of resonant reflectors and how they can effect laser output. He has calculated diffraction patterns of various optical systems and how apodizing (tapering of illuminations) apertures affects system performance. He has tried to improve the way laser acceptance specifications are written. For example, trying to transmit all the energy generated by a laser to the output may be counterproductive, because the energy squeezed out increases beam divergence.
Expert has worked on various detectors and receivers for laser and other optical systems ranging from photomultipliers, to avalanche indium gallium arsenide (InGaAs) detectors, to imaging detectors such as vidicons and image intensifiers. Many of the detector techniques are similar to those required for nuclear particle detectors such as proportional counters and solid state nuclear detectors. He has worked on receivers and low noise amplifiers. The InGaAs detector was used to receive the eyesafe rangefinder wavelength of 1.54 micrometers. His work in reducing the effects of background radiation to receiver noise has included using image tubes to reduce the effective field of view, narrow bandwidth filters both in the optical domain and by coherent reception, range gating, and signal integration. Many of these methods used Expert's previous radar knowledge.
Coherence of laser light results in speckle, which is similar to radar scintillation on a small scale. By understanding speckle, Expert has been able to convert speckle specifications for certain laser radars into laser specifications on linewidth and modulation. For the continuous wave CO2 laser radar, he used coherent detection to obtain greatest receiver sensitivity. He has worked on the optimal processing of such signals and specifying receiver parameters to optimize them.
The most controlled form of laser Q-switching uses electro-optical shutters that require polarizers, waveplates, and electro-optical crystals. Expert has designed and selected such optics, and he has a number of publications in the field. He understands propagation in crystalline materials. Even dichromic polarizers like Polaroid film depend upon the behavior of crystals. Another key to the use of polarized light is how the polarization state gets transformed as the light passes through wave plates and rotators. Expert is an expert in those methods. He is the inventor of a missile guidance system in which position in a beam gets encoded into a polarization state of a laser beam.
Expert is knowledgeable about the design of optical thin films used for filters, anti-reflection coatings, high reflectivity coatings, polarizers, and other purposes. He has designed various coatings of these types. He has studied how the design of coatings may affect the high energy damage thresholds of coatings. His major effort in optical thin-films has been to design polarizers for laser systems in order to obtain higher damage threshold and lower cost than possible with birefringent materials. He has a number of publications on the subject. At one time he was in charge of running a small optical coating facility.
Expert's involvement in optical warfare ranges from rangefinders and designators to optical measures and countermeasures. Because of national security classification, such topics are not suitable for telephone consultation.
Expert has experience in the generation of new frequencies from a laser output using harmonic generation and other parametric processes. Harmonic generation is usually achieved with crystals similar to those used for electro-optics. Expert understands the optical properties of such crystals and how to arrange for the "phase matched" conditions necessary for efficient conversion. He has studied phase conjugation using stimulated Brillouin scattering, looking into the conditions that govern its successful operation. He has worked on the conversion of neodymium laser radiation at 1.06mu-m into 1.54mu-m radiation for an eyesafe laser by Raman conversion. Because there are competing processes, particularly from the same stimulated Brillouin scattering useful for phase conjugation, he had to look into this competition. He found out that there could be a cooperation between the two competing processes using the means described under interferometry.
Many of the laser systems Expert has worked on produce radiation in infrared regions of the spectrum. They are often used in conjunction with thermal imaging devices. For these reasons Expert has had to understand and work with infrared devices. In particular, he looked into detectors for the 1.54 micrometer "eyesafe" rangefinder, and their associated amplifiers.
Expert has used interferometers and interferometry for a number of purposes. One was to characterize laser rod performance by means of their interferograms. He found that vendors did not interpret the interferograms properly, and shipped non-compliant rods. He has used shear interferometry to examine the wavefronts of laser outputs. He used a Fabry-Perot infrared interferometer to search out nonlinear optical interaction problems in a laser rangefinder using Raman conversion to transform the laser wavelength to an eyesafe wavelength.
Expert has modulated optical waves using various materials for electro-optical (Pockels) cells. He has also used acousto-optics for that purpose. In addition, he had developed high voltage pulsers (modulators) for use with pulsed radar and laser systems. (As a radio amateur, he is familiar with various ways of modulating radio frequency carriers for use in communications).
Because the principles of wave propagation transcend the specific form of wave, Expert has been able to delve into a number of fields. For example, the effect of atmospheric temperature profile on the propagation of airport noise. Expert has given seminars on electrical transmission lines to coworkers, developed multilayer thin-film calculations, used a Smith chart to aid in calculation, and analyzed and designed systems for the propagation of Gaussian laser beams from visible to infrared wavelengths.
Expert may consult nationally and internationally, and is also local to the following cities: Los Angeles, California - San Diego, California - Long Beach, California - Santa Ana, California - Anaheim, California - Riverside, California - Bakersfield, California - Glendale, California - Huntington Beach, California - San Bernardino, California
|Year: 1956||Degree: PhD||Subject: Electrical Engineering, Physics & Math||Institution: California Instituteof Technology|
|Year: 1951||Degree: BEE||Subject: Electrical Engineering||Institution: City College of New York|
|Years: 1989 to Present||Employer: Undisclosed||Title: Independent Consultant||Department:||Responsibilities:|
|Years: 1972 to 1989||Employer: Hughes Aircraft||Title: Senior Scientist/Engineer||Department:||Responsibilities:|
|Years: 1971 to 1971||Employer: Nucleonic Data Systems||Title: Assistant to President||Department:||Responsibilities:|
|Associations / Societies|
|Expert is a Senior Member of IEEE and a member of three honorary professional fraternities.|
|Licenses / Certifications|
|He is a registered PE (Electrical) in California.|
|Publications and Patents Summary|
|He holds a number of U.S. patents and has published in the fields of lasers and optics.|