<title>Dynamic characteristics and reliability of gain-coupled InGaAsP laser diodes</title>

Abstract

Dynamic characteristics of partly gain-coupled multiple-quantum-well InGaAsP distributed feedback laser diodes (LD) have been investigated. Relative intensity noise measurements were done and key dynamic parameters (differential gain, <i>K</i>-factor) were estimated. From time-resolved frequency chirp measurements, the chirp components and the chirp parameter were extracted. Several tens of devices were characterized. Although all the devices were of the same structure and dimension, their dynamic parameters were spread in values. It is believed, that the spread is due to the limited device processing accuracy. The correlation between the dynamic parameters was observed. The <i>K</i>-factor and differential lifetime were found to be correlated mutually and with the differential gain, which indicates that the latter plays an essential role in determining the variance of dynamic parameters. It was shown that the increase of the coupling coefficient results not only in both the oscillation and damping frequency increase, but also in the decrease of the amplitude of the time-resolved frequency chirp oscillation. LDs were subjected to the accelerated aging by applying at 100 °C the 150-mA bias for 1800 h. The degradation of the threshold current, the efficiency, and the amplitude ,of the time-resolved frequency chirp oscillation was observed.