Spontaneous emission behavior and its injection level dependence in three-dimensional microcavity surface emitting lasers

Abstract

Vertical-cavity surface emitting lasers (VCSELs) are expected to be used as light sources in two-dimensional array optoelectronics because of their structure and probable characteristics. The control of spontaneous emission by wavelength-size microcavities is effective in lowering the threshold of surface emitting lasers. The control of spontaneous emission using the spontaneousemission factor of three-dimensional microcavities was presented by the authors in previously done work. This paper reports on further progress in the analysis of the spontaneous-emission factor. The standing wave distribution inside a planar or three-dimensional microcavity is first investigated. Increase in the spontaneous-emission factor and control of the optical mode taken out of the microcavity are estimated under the increased optical confinement factor due to varied external boundary conditions of the distributed Bragg reflector (DBR). The variations of the spontaneous emission and output characteristics associated with injection level are discussed. It is shown that the spontaneous-emission factor varies with cavity resonant wavelength and the injection level affects the output optical characteristics.