We examine the internationalization processes of a sample of photonics companies, using in-depth interviews conducted with twenty-two CEOs. The texts of these interviews were appraised by using content analysis, combined with a grounded theory approach. In this way, the internationalization theory was critiqued and some insights developed into the international strategy process. Some salient findings emerged, such as that cluster externalities had a positive impact on the internationalization of firms within the cluster, and the degree of strategic vulnerability that cluster firms faced from developing-country competitors. These findings are discussed in relation to their research and managerial implications.