| 摘要 |
<p>Disclosed is a technology for detecting damaged VCSELs in a short time and at low cost. A multi-mode VCSEL that has yet to suffer ESD damage exhibits an emission spectrum showing a number of peaks corresponding to the structure of the active layer (MQW) and the upper and lower reflectors (DBR). Meanwhile, a VCSEL that has suffered ESD damage and has a damaged active layer exhibits an emission spectrum showing fewer peaks that the initial number of peaks, for example two or fewer peaks. Thus, the emission spectrum is analysed using a light spectrum analyser and if the number of peaks totals a predetermined number, for example two or fewer peaks, ESD damage is determined to have occurred.</p> |
