| 摘要 |
<p>In some applications of distributed feedback (DFB) lasers, it is important that the coupling constant kappa be closely controlled. This is not easily achieved, frequently resulting in low yield of acceptable devices. I have discovered that variations in kappa can be reduced if the DFB laser is designed such that the thickness ts of a spacer layer (between the active layer and the Bragg grating) is within about +/- 10% of the value to/(1 - alpha ), where to is the modal decay length, and alpha is a parameter which characterizes the fractional variation of to with fractional changes in layer thickness. <IMAGE></p> |
