Spin‐polarized surface‐emitting lasers

Abstract

We investigate the growth, fabrication, and characterization of an electrically-injected spin-polarized laser utilizing an Fe/n + -Al 0.1 Ga 0.9 As Schottky tunnel barrier for efficient spin injection into an InGaAs quantum well vertical-cavity surface-emitting laser. A threshold current reduction of 11% and maximum degree of circular polarization of 23% are observed for a 15 µm mesa diameter laser at 50 K. The lack of a threshold current reduction and circularly-polarized electroluminescence in similar nonmagnetic and Fe control lasers provides further evidence of spin injection.

1300 nm optically pumped quantum dot spin vertical external-cavity surface-emitting laser

“…31,32 The attributes of spinVCSELs offer the potential for new applications such as reconfigurable optical interconnects, spin-dependent switches for optical telecommunications, quantum information processing and data storage, quantum computing, bandwidth enhancement, high speed modulators, cryptography of optical communication, circular dichroism spectroscopy, biological structure studies, biomedical sensing, and advanced optical devices. 8,15 Spin-polarized VCSELs have previously been demonstrated at short wavelengths either electrically driven via spin-polarized current into quantum dot (QD) 29,32,33 and quantum well (QW) 34,35 active regions or optically by optically pumping a QW 18,20,27,28,36,37 or bulk 17 VCSEL. In contrast, at telecoms wavelengths, we are only aware of one recent report of a 1300 nm optically pumped QW spin-VCSEL at room temperature.…”