In this paper, a simple method for measuring current-induced frequency modulation characteristics of semiconductor lasers is reported. In this method, no complicated optical and measuring system is needed and is easy for practical application. The experimental results in low modulation frequency range show 0.2% in accuracy is achieved and the system is fit for measuring the current-induced frequency modulation characteristics of semiconductor lasers.
This article firstly gives out when the phase modulation amplitude is at best value of homodyne demodulation using phase generated carrier, and then presents three methods that can be realized to get the best value. Some differences based on practicality are made among them, and a method which is easy to be implemented by digital circuits, is chosen to be carried out by digital circuits. Also this paper gives out simulation analysis and real experiment results. The error range is from -3.80% to 2.11% with real system. The origins of the error limiting the accuracy are discussed.