INASP INGAASP PERIODIC GAIN STRUCTURE FOR 1.5 MU-M VERTICAL-CAVITY SURFACE-EMITTING LASER APPLICATIONS/

We have studied the capabilities of chemical beam epitaxy (CBE) to pro duce high-gain media for long-wavelength (1.5 mu m) vertical cavity su rface emitting lasers (VCSELs). Using a parameter pair of low growth t emperature and small V/III ratio the integration of up to 15 highly st rained (1.78%) InAsP quantum wells (QWs) into a periodic gain structur e (PGS) is successfully demonstrated. In this work we present data of atomic force microscopy (AFM), X-ray diffraction, reflectivity and ele ctro-luminescence measurements that prove the very good structural and optical quality of this CBE grown PGS. As an alternative to conventio nal multi quantum well(MQW) systems as active layers, a high-performan ce PGS may be used in a VCSEL structure to reduce the very strict requ irements on the InP-based distributed Bragg reflectors (DBRs) or to in crease the achievable output power. Due to the use of thickness-reduce d InP-based DBRs in conjunction with a PGS as the active region the fa brication of fully epitaxial grown long-wavelength VCSELs might also b e possible with CBE. (C) 1998 Elsevier Science B.V. All rights reserve d.