STRUCTURAL DEPENDENCE OF 3-PHASE-SHIFT DISTRIBUTED-FEEDBACK SEMICONDUCTOR-LASER DIODES AT THRESHOLD USING THE TRANSFER-MATRIX METHOD

The three-phase-shift (3PS) distributed feedback (DFB) laser is known to have improved performance over the lambda/2 DFB laser because the s patial hole burning effect is suppressed. When optimizing the structur al design of the 3PS DFB laser, the threshold gain difference and the field distribution along the laser cavity have been selected as the de sign criteria. Using the transfer matrix method, it is found that the optimum phase-shift values and their positions are in trade-off when o ne attempts to optimize both the gain difference and field uniformity simultaneously.