Gain measurement of semiconductor laser diodes: requirements for the wavelength resolution and sensitivity to noise

The gain-measurement methods of Hakki-Paoli and Cassidy are investigated theoretically with respect to accuracy of gain evaluation and sensitivity to noise. The Cassidy method proves to be less sensitive to noise than the Hakki-Paoli method if an additional averaging procedure is introduced. The results presented permit easy establishment of the required performance of an appropriate measurement system.