Absorption loss properties and Stokes shifts of InGaAs-based self-assembled well-wire-hybrid quantum structures

Abstract

Stokes shift is an important physical property relating to emission and absorption of light-emitting diodes, which reflects photon self-absorption situation and affects the device performance. Nowadays, it is becoming more and more difficult to change Stokes shift and relevant physical properties to further improve device performance with traditional quantum structures from increasing requirements in application. Therefore, hybrid quantum structures have attracted an attention recently. However, the properties related to Stokes shift in the new configurations have not been revealed so far. In this paper, we investigate the absorption loss and Stokes shift of the newly proposed InGaAs self-assembled well-wire-hybrid quantum structure. By designing a new absorption loss measurement approach, we can conveniently extract internal optical mode loss of a quantum structure and explore its Stokes shift with the measured absorption spectra. Our findings reveal that the presence of quantum wires in the structure can significantly reduce the Stokes shift difference between transverse electric (TE) and transverse magnetic (TM) polarizations from 66.7% for a traditional quantum well to 15.4%. It suggests the potential for the reduction of TM-mode photon self-absorption in a compressive-strain quantum structure. This phenomenon offers new prospects for the development of polarization-insensitive devices.