Large Spontaneous Emission Factor of 0.1 in a Microdisk Injection Laser

Abstract—A large spontaneous emission factor of 0.1 was eval-uated in a 1.56- m-GaInAsP microdisk injection laser operating under continuous-wave condition with a threshold current of 50 A. Some clear evidence of the large spontaneous emission factor, i.e., superlinear light–current characteristics and nonclamped car-rier–current characteristics, were observed. It was confirmed that the matching of the lasing wavelength to the spontaneous emission allowed larger spontaneous emission factor. Index Terms—GaInAsP, microcavity, microdisk, spontaneous emission control, spontaneous emission factor, whispering gallery mode. THE ENHANCEMENT of the spontaneous emission factor(sometimes called) in microcavity semiconductor lasers will lead to a large light power of the lasing mode below threshold and a nonclamped carrier density at threshold [1]–[3]. Microdisk [4], [5], a kind of whispering gallery (WG) mod