Have you read any technical information on LWLG's tech? Read this - it is the recently publicized patent application for the integrated (driver-less) laser/modulator device. Methods of manufacturing are discussed.
Your question about yield may be valid, but I don't think that just because you don't have a satisfactory answer that anyone should conclude that the tech is garbage. Try asking the company.
LWLG has been discussing the tech with various companies, including fabs, for years (under NDAs). I'm betting that Lebby et.al. have satisfactorily addressed your question already. You can place your own bet, or not.