Paper 2.10: A.J. Schell and N. Bloembergen, “Second harmonic conical refraction,” Optics Comm. 21, 150–153, 1977.

This note announces the observation of the effect predicted eight years earlier in the preceding paper. The subject matter was of purely academic interest and attracted no attention from the quantum electronics community. My graduate student Jane Schell had no competition and was able to complete a delicate investigation with care. The complete results were published as, “Laser studies of internal conical diffraction III, second harmonic conical refraction in a-iodic acid,” A.J. Schell and N. Bloembergen, Phys. Rev. A, 2592–2602, 1978. This paper, not reprinted here, is the third in a series. The first two parts report a quantitative determination of intensity patterns in conical refraction obtained with a diffraction limited helium-neon laser. To my knowledge, the phenomenon of second harmonic external conical refraction, mentioned in the preceeding note, has not been reported to date.

Jane Schell married Peter P. Sorokin, another former Ph.D. student of mine. She continued her scientific research for many years at the IBM Research Laboratories in Yorktown Heights, New York. Peter Sorokin did his doctoral research in my laboratory on a problem in nuclear magnetic resonance in the mid -fifties. He is the inventor of the dye laser and has made several other pioneering contributions to the field of quantum electronics. He is an IBM Watson Fellow. It was a pleasure to honor him at a celebration on the occasion of the 25th anniversary of the dye laser which was held a few years ago at the IBM research laboratories in Yorktown Heights.