1.3-μm Range Metamorphic InGaAs Laser With High Characteristic Temperature for Low Power Consumption Operation

We demonstrated a 1.3-μm-range laser with a high characteristic temperature (T₀ = 220 K) and the highest operating temperature (200 °C) ever reported for a metamorphic laser. The temperature characteristics were greatly improved by inserting a p-InGaAlAs electron stopper layer. In addition, we realized a high f_r value with a low injection current using a short cavity (L = 200 μm) laser operating at a high temperature. The bias current at 10 Gbit/s and 85 °C was only 15 mA. These results show that a laser with a metamorphic buffer on a GaAs substrate is a good candidate as an uncooled light source with low power consumption.

I. Introduction

Network traffic is increasing worldwide. There is a strong demand that the electric power of optical communication systems be used efficiently. Conventional InP-based lasers with InGaAsP multiple quantum wells (MQWs) are sensitive to the ambient temperature and require additional temperature control devices. The power consumption of light sources can be greatly reduced by removing the laser module temperature controllers and suppressing the increase in the drive current at high temperature. This makes it important to improve the temperature characteristics. To achieve such an improvement, it is important to reduce the carrier overflow from an MQW at high temperatures. Therefore, a large conduction band offset is essential. With this aim, InGaAlAs material has been studied as a replacement for the conventional InGaAsP material [1]. The characteristic temperature of this material system is between 80 and 95 K.