10-Gb/s - 120-C Operation of 1.3-um AlGaInAs-MQW-FP-LD with Ru-doped InP Buried Heterostructure

Abstract

We have developed the first 1.3-µm AlGaInAs-MQW-FP-LD with Ru-doped InP buried heterostructure by narrow-stripe selective MOVPE. SIMS measurements revealed that the Ru-doped InP suppressed Zn diffusion from Zn-doped InP in comparison with Fe-doped InP. The LD operates up to 170 °C. 10-Gb/s operation up to 120 °C and more than 3,500-hour reliability under 85-°C APC test has been successfully achieved. IntroductionThe compact optical transceiver modules such as XENPAK, X2, XFP, SFP, etc., are keys for the emerging metro/IP and storage-area network systems. These components are so small and used under severe environment that their power consumption and heat radiation are quite important issues. Thus compact light source devices without a thermoelectric cooler, which consumes most of the power, have been strongly needed. Recently, an AlGaInAs-MQW based directly modulated light source (DML) [1]- [5] becomes to be employed for such applications. Compared to the InGaAsP/InP material system, the AlGaInAs/InP material system is suitable for obtaining high-speed modulation at high temperature due to its large conduction band offset and high relaxation oscillation frequency (f r ) related to its higher differential gain. To improve its modulation bandwidth and operation current, a semi-insulating InP buried heterostructure (SI-BH) compatible to such Al-based active stripe is indispensable. Many efforts have been made to achieve a 10-Gb/s direct modulation at high temperature (>85 °C). We reported the first AlGaInAs-MQW-DFB-LD with SI-BH structure developed by our original narrow-stripe selective MOVPE [4][5]. In such SI-BH structure, Fe has been used as electron trap. It has, however, a problem of inter-diffusion between Zn in InP under epitaxial growth. It increases leakage current, which becomes to be serious especially under high temperature condition. Recently, ruthenium (Ru) becomes to be attracted attention as the promising alternative to Fe due to its low interdiffusion potential [6]- [8]. It is therefore expected that Ru-doped InP will provide an ideal high temperature performance to such Al-based uncooled devices.In this paper, we report the first 1.3-µm AlGaInAs-MQW-FP-LD with Ru-doped InP buried heterostructure (Ru-BH) developed by our original narrowstripe selective MOVPE technique [4]. The static and 10 Gb/s modulation performance under high temperature conditions were evaluated. Its practical reliability was also demonstrated.