Extremely low threshold InGaSsp/InP DFB PPIBH laser diode
We report on an extremely low threshold InGaAsP/InP DFB laser realized by an MOCVD/LPE hybrid process.
1 Gbit/s automatic-power-control-free zero-bias modulation of very-low threshold MQW laser diodes
The first 1 Gbit/s, automatic-power-control-free zero-bias modulation has been successfully demonstrated using very low-threshold GaAs/AlGaAs MQW lasers. A stable multi-longitudinal mode oscillation due to zero-bias modulation was also observed. This result simplifies driving circuitry and is an important step towards realisation of high-speed and high-density optoelectronic integrated circuits.
Properties of intensity noises of laser diodes due to reflected waves from single-mode optical fibers and its reduction
The intensity noises due to reflected waves from the single-mode fibers were found to be about 10 dB larger than those of the multimode fibers due to the large coupling coefficient to a specific mode between the laser and the coupled optical fibers. The noise enhancement of about 20 dB was observed in the both types of fibers when the direct modulation was applied for the laser diode with reflected waves, and the lower cutoff modulation frequency related to noise enhancement was found to be about 10 kHz. It was found that the noise of the narrow stripe laser is about 10 dB smaller than that of the wide stripe laser, and it was estimated that the optical isolator with a reverse isolation loss of 30 dB provides noise reduction of 40 dB.