1．前言为制成小型高效可见光激光光源，已有多种方案正在活跃地开展研究，其中绿光激光器已经实用化，微片激光器已有市售品。蓝光激光器虽在各种学术会议上有道，但是还未出现实用激光器。在这样的背景下，比绿光波长短、在更多领域能够使用的小型蓝光激光器的实用化研究也开 1. Preface There are a number of programs that are being actively pursued to make small, efficient visible laser light sources, of which green lasers have become commercially available and those available on the market have been commercially available. Although the blue laser in a variety of academic conferences, but there is no practical laser. In such a background, practical research on small blue lasers, which have a shorter wavelength than green light and can be used in more fields, is also on