Gain Factor and Internal Loss of GaAs Junction Lasers

Terahertz Pioneer: Jun-ichi Nishizawa “THz Shogun”

“…The semiconductor optical maser, patented by Nishizawa in 1957 [32], was realized in 1962 by Robert Hall at General Electric, USA [68] and Marshall Nathan at IBM, USA [69]. Nishizawa added GaAs devices shortly afterwards [70]- [72], and demonstrated millimeter-wave modulation of the optical energy in 1968 [73]. Again, remarkably, Nishizawa also developed the concept of using a focusing optical lens implemented with a graded index sheath for efficient transmission of light way back in 1964 [74]- [76], two years before Charles Kao and George Hockham at Standard Telecommunications Laboratories, Essex, England launched the optical fiber revolution with their classic paper [77].…”