Gisela Eckhardt

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Gisela Eckhardt (born October 28, 1926 in Frankfurt am Main ; † January 30, 2020 in Malibu ) was a German physicist and co-developer of the Raman laser .

Life

Eckhardt grew up as the child of an electrical wholesaler in Frankfurt, who died when she was only 13 years old. The reading of Usturz im Weltbild der Physik by Ernst Zimmer aroused an interest in the natural sciences in the twelve-year-old student at the Frankfurt Wöhlerschule .

After graduating from high school, she studied physics at the Johann Wolfgang Goethe University in Frankfurt am Main . She graduated with a diploma in 1952, with a diploma thesis on the expansion of the range of application of Christiansen filters into the infrared. In 1958 she received her doctorate . The long delay in her doctoral thesis was partly due to obstacles her doctoral supervisor Marianus Czerny put in her way. The dissertation deals with heat transport in glasses up to 450 degrees Celsius. Eckhardt quickly realized that she had to measure up to much higher temperatures for this, which required platinum electrodes. Eckhardt soon succeeded in organizing this on his own initiative as a loan from the industry, but it took her doctoral supervisor considerably longer to be convinced of the necessity.

She then went to the United States with her husband Wilfried, who had also recently received a doctorate in physics. There they initially worked for the electronics company RCA , where they had to go to another laboratory in the group, since married couples were not hired there at the time. While her husband was in the main laboratory in Princeton, she was in the semiconductor laboratory in Somerville, for slightly lower pay. She succeeded in inventing an improved method for polishing silicon wafers, but this did not advance her career. She was openly given to understand that as a woman, she would have to work twice as hard as a man to be promoted.

In 1960, like many other RCA employees who were dissatisfied with management and pay, she moved to California's booming high-tech industry, and in 1960 she and her husband accepted a much more generous job offer from Hughes Research Laboratories in Malibu . Here she was involved in the development of the first Raman laser in 1962 , which used nitrobenzene as a liquid laser medium and a ruby ​​laser with Q switch as a pump laser. Both ruby ​​lasers ( Theodore Maiman , the first laser) and Q-switching ( Fred McClung , based on an idea by Robert Hellwarth ) had previously been developed at the HBW in pursuit of the development of laser applications for the military (distance measurement). Eric Woodbury and William Ng found in another Hughes Aircraft laboratory a strong signal at an unusual wavelength (longer than the ruby ​​laser), which Eckhardt, who had experience in Raman spectroscopy, attributed to the nitrobenzene of the saturable absorber in the Q-switch and to a stimulated Raman Effect . With the Raman laser it was possible to generate laser beams on a wide range of wavelengths. The patent listed Woodbury and Eckhardt as inventors and took three attempts before it was approved in 1968, after Charles Townes , among others, submitted a positive opinion (the patent office criticized a lack of inventive step). While Eckhardt estimates that the company earned more than $ 1.5 billion from the invention, like her colleague, she only got $ 100 according to common practice at the time. Eckhardt was also significantly involved in the implementation of the first diamond-based Raman laser as early as 1963.

Soon after the patenting, she moved for personal reasons to a department that developed methods for converting alternating current into direct current and vice versa in power electronics, and where her husband later became her laboratory manager. She turned down an offer to move with her husband to a Max Planck Institute in Germany because she was not offered adequate pay - they only wanted to pay her a quarter of her husband's salary. Among other things, she dealt with processes in gas discharge tubes (liquid metal arcs), with applications in power electronics (high-voltage direct current transmission and the necessary conversion from alternating to direct current and vice versa), and the production of ohmic contacts on semiconductors with the help of lasers. In 1982, she left the Hughes Laboratories. She turned down various offers for professorships.

Together with her husband, she successfully ran various photo shops in the USA as a franchisee.

From 1977 to 1979 she was on the Executive Committee of the Gaseous Electronics Conference, where she organized roundtables. In 1982 she was co-editor of Applied Physics A (Solids and Surfaces). In 2014 she gave a keynote speech at the Europhoton conference in Zurich on the occasion of the 50th anniversary of her discovery.

Eckhardt lived in Malibu and in Frankfurt-Sachsenhausen.

literature

  • Alumni in portrait. Questions to Dr. Gisela Eckhardt. In: Insight. The magazine for alumni & friends [of the Johann-Wolfgang-Goethe University], issue 37, November 2017, pp. 12-13.

Web links

Individual evidence

  1. ↑ Valdas Pasiskevicius, Richard Mildren, David Burman: Gisela Eckhardt and the Raman laser , Physics World October 2015
  2. ↑ Gisela Eckhardt, RW Hellwarth, FJ McClung, SE Schwarz, D. Weiner, EJ Woodbury: Stimulated Raman Scattering From Organic Liquids . Phys. Rev. Lett. 9, 1962, pp. 455-457
  3. ↑ Woodbury, Ng, Proc. Inst. Radio Engineers, 50, 1962, 2367
  4. ↑ a b Sascha Zoske: The misunderstood laser pioneer. In: FAZ.net . November 20, 2015, accessed November 27, 2015 .
personal data
SURNAME Eckhardt, Gisela
ALTERNATIVE NAMES Elsholtz, Gisela
BRIEF DESCRIPTION German physicist and inventor
DATE OF BIRTH October 28, 1926
PLACE OF BIRTH Frankfurt am Main
DATE OF DEATH January 30, 2020
Place of death Malibu