Currently, wafer-fusion technology represents an effective technique for enhancing the performance of long-wavelength vertical cavity surface-emitting lasers (VCSELs) based on classical double heterostructures with multi-quantum well active regions. Using the example of 1310 nm wavelength VCSELs, we demonstrate the status of this technology for wafer-level scale, wavelength-controlled devices with high performance, capable of operation in a wide temperature range up to 90 • C with single-mode output power levels in excess of 1 mW and a side mode suppression ratio (SMSR) in excess of 40 dB. No degradation was observed in a qualification lot that operated at 10 mA and 90 • C for 2000 h.

InP-aad GaAs-based air-gap vertical cavity suface emitting laser (VCSEL) StrUcNres are very impoaant for the fabrication of tumble VCSELs. Generally air-gaps are formed by undercutling the sacrificial layer bethe active cavity material and the top DBR using either chemical or dry etching. The resulting air-gap structures are very fragile and special precautions need to be inmdueed in the fabrication proeess, also application of these devices In this paper we study long wavelen@h fused InGaAsPIAIGaAs air-gap VCSEL s t r o c m which are obtained in-siN by the localised wafer fusion technique. In this sNdy we have used InGaAsPnnP active cavity material and uodoped AlGaAsiGaAs DBRs -all grown by metal mgaoic chemical vapor deposition (MOCVD) at 650T. InGaAsP/lnp material is g m m with B eonsmt group V clcmmts composition throughout the struchme. It includes a strain compensated quanhrm well structure with I% wmpressivc strain in the wells and 0.8 % tensile strain in the barriers. The peak of the phobluminescence spec" is at 1550 "Air gap of thickness d was formed by etching a 80 lun diameter recess in Le active m e r i d before fusion (Fig.1). Cavity mode of the resulting VCSEL structure is well centered in lhs stopband ofthe DBR. (Fig.2). Pulsed aod CW single mode emission with mere than 30 dB Wavebngth. nm Fig. 2 Fig.3.side mode suppression ratio were obtained under optical pumping using standard laser diodes at 980 nm. The threshold optical pumping power of 3 mW was typical for the devices used in this study (Fig 3). Caviry mode wavelength of the airgap stmchlre at 1521 nm was measured below and above laser threshold (Fig.4). Cavity mode at 1523 nm both below and above threshold waz measured when air gap was field up with acetone. Due to rapid evaporation of acetone cavity mode shifts back to 1521 m in 3-5 min. Experimental results with VCSEL smchlres having different air gap geometry and using various liquids lo fill them up will he presented as well. CThK2Nwel IoGaAsPlAlGaAs moltiplewavelength electricsUy pumped vertical cavity lasers emitting in the 1.5 pm wavebandMultiple wavelength v d c a l cavity surface emitting lasers (VCSELS) emitting in the 1.5 pm waveband may become light sources of preference LI~ fuNre wavelength division multiplexing (WDM) metropolitan and local area networks. In this paper wc present a novel approach to the multiple wavelength VCSEL fabrication which is based on the inlraduction of air-gaps in double fused VCSEL strucNres. The fabrication process ofthese devices is similar to the processing of double fusod VCSELs with in-situ built-in lateral optical and current confmement. The only difTerencr is that a h first p-p fusion and InP substrate removal we form B recess 8s shown on Fig.1 hy 4rctively etching part of the InP-based " E . This m a t e d is grown by gas sourcc MBE and wnsists of six InGaAsP strained q u " m wells that are centered in a 312 h InP cavity. 1.5 periods of n-and pInGaAsPilnP DBRs n e also gmw on n-and p-sides of this cavity. In this study we selectively etched one...